Inkjet-Printed Sensors Powered by Wireless Power Transfer for Biomedical Monitoring: A Decade of Evidence — A Systematic Review

Inkjet-Printed Sensors Powered by Wireless Power Transfer for Biomedical Monitoring: A Decade of Evidence — A Systematic Review | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Systematic Review Inkjet-Printed Sensors Powered by Wireless Power Transfer for Biomedical Monitoring: A Decade of Evidence — A Systematic Review M. Muklasur Rahman Opu, Md. Ruqnuzzaman This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8464801/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Over the past ten years, inkjet-printed electronics have advanced quickly, making it possible to create flexible, biocompatible, and reasonably priced biomedical sensors that are appropriate for ongoing, covert physiological monitoring. Simultaneously, batteryless, ultra-thin, and very compliant biomedical systems have been made possible by wireless power transfer (WPT) technologies, such as inductive coupling, near-field communication (NFC), and radio-frequency (RF) energy harvesting. For next-generation wearable and implantable platforms that need mechanical softness, long-term stability, and continuous operation without heavy, inflexible batteries, the convergence of these two domains is very important. Ten years' worth of research on inkjet-printed sensors with wireless charging systems for biomedical monitoring is compiled in this systematic review (2015–2025). We created a structured Google Scholar search strategy utilizing Boolean operators, categorized keyword sets, predetermined inclusion and exclusion criteria, and methodical screening processes in accordance with PRISMA 2020 principles. In order to enable a variety of biomedical applications, such as biochemical sweat sensing, electrophysiology, wound monitoring, hydration detection, thermal mapping, and multimodal physiological surveillance, the analysis highlights significant developments in printable materials, fabrication techniques, sensing architectures, and WPT modalities. Significant obstacles still exist in the sector despite evident advancements, including restricted wireless power supply, mechanical deterioration under stress, ink instability, substrate–ink mismatch, biosafety concerns, and a lack of clinical validation or standardized testing. Hybrid additive manufacturing, sustainable and biodegradable printed materials, self-healing conductors, ultra-low-power electronics, multiparametric sensing arrays, and AI-driven signal interpretation are examples of emerging potential. All things considered, this analysis highlights the revolutionary potential of entirely batteryless, wirelessly powered, inkjet-printed biomedical systems and offers a thorough road map for bringing them closer to clinical-grade dependability and broad acceptance. Biomedical Engineering Inkjet printing printed electronics wireless power transfer NFC powering flexible biosensors wearable biomedical sensors batteryless physiological monitoring Figures Figure 1 1. Introduction Over the past ten years, biomedical sensing technologies have experienced a significant shift due to the emergence of ultrathin, flexible, and skin-conforming devices that can continually monitor physiological data with little effort on the part of the user. Flexible electronics can fit onto any curved surface, such as human skin and organs, without changing their properties, making them suitable for wearable or implantable healthcare and monitoring systems [1].Conventional wearable technology frequently uses battery-operated power modules and stiff electronic components that limit wearability over an extended period of time, impair comfort, and present safety issues in implantable settings. On the other hand, lightweight, mechanically compliant, and geometrically flexible biosensor platforms that naturally interface with the human body are made possible by printed electronics, especially those made by inkjet printing. Electrochemical biosensors are the best for designing and making flexible and wearable sensors due to their convenience, quick response, portability, and natural downsizing [2]. Digital pattern programmability, maskless and non-contact deposition, little material waste, quick prototyping, and compatibility with a variety of substrates and functional inks are some of the benefits that inkjet printing offers over conventional microfabrication methods. Finally, inkjet printing reduces manufacturing procedures and setup expenses, making large area sensor fabrication rapid and cost-effective [3].This adaptability makes inkjet printing a crucial enabler for next-generation wearable and epidermal biosensing systems by enabling the quick manufacture of electrodes, interconnects, antennas, microfluidic channels, and biochemical sensing layers. Due to its cost efficiency, mass production, simplicity, and environmental sustainability, flexible sensor technology, notably inkjet printing on flexible substrates, is gaining popularity[4]. One of the most enduring issues in the creation of soft, skin-mounted, or implantable biomedical systems is powering. This study will implement and assess a power device for future integration with an implantable biomedical system [5].Conventional batteries pose concerns such as limited operational lifetime, frequent recharging requirements, mechanical rigidity, physiological incompatibility, possible leakage, increased system thickness, and constraints on physical flexibility. An attractive substitute is wireless power transfer (WPT), which is accomplished by RF energy harvesting, near-field communication (NFC), and inductive coupling. Implanted bioelectronics require wireless power transfer because cable connections are impractical [6]. WPT makes it possible for completely passive, maintenance-free, and mechanically compliant sensor platforms that can run continuously by doing away with the requirement for on-board batteries. Research that integrates these fields is still few and dispersed, despite significant developments in materials, printing techniques, antenna design, biosensing techniques, and wireless powering. Existing research often focus on a particular dimension—such as printing conductive ink patterns, improving antenna designs, or demonstrating novel biochemical sensing modalities—without offering an integrated, system-level study. Wireless biosensing is important because it can monitor physiological data in real time without wires [7]. The translational potential of fully printed, battery-free biomedical devices is constrained by the lack of a unified knowledge. This systematic review addresses this knowledge gap by examining inkjet-printed sensors and wireless power transfer technologies for biomedical monitoring over 10 years. Increasing biological applications require high-portable, low-invasive, real-time, and long-term sensing [8].The review describes the fundamental ideas, new developments in technology, biomedical uses, performance constraints, and new prospects in this multidisciplinary sector. This sensor's power efficiency, adaptability, and cost effectiveness show that inkjet-printing may create green, high-functioning devices as alternatives to silicon-based methods[9]. Our goal is to provide a cohesive framework that facilitates further development of biomedical monitoring systems that are completely battery-free, scalable, and clinically dependable. 2. Background 2.1 Inkjet-Printed Electronics and Biomedical Sensors One effective and adaptable additive manufacturing method for creating next-generation biomedical sensors is inkjet printing. Wireless device production and deployment, especially flexible or soft ones, require design, materials, and efficient architectures [10]. It works as a drop-on-demand, digitally controlled deposition method that allows for the accurate application of functional materials, such as conductive, dielectric, or biological ones, onto a variety of surfaces. The sensor converts cardiac vibrations into electrical signals[9].Inkjet printing is particularly appealing for flexible and wearable biomedical applications because it enables quick, maskless patterning with little material consumption, in contrast to classic photolithographic techniques. Key Advantages Inkjet printing has a number of advantages that make it a top fabrication technique for soft, conformal biosensing systems: Maskless, non-contact patterning: Lowers the chance of contamination and gets rid of expensive lithographic stages. Minimal material waste (<10%): Substantially less than subtractive manufacturing methods. Rapid design iteration: Sensor geometry can be changed almost instantly thanks to digital design. High printing resolution (down to 20–50 μm): Appropriate for microfluidic features, electrodes, and antennas. Low-cost prototyping with scalable manufacturing: Suitable for both industrial roll-to-roll processing and laboratory prototyping. Integration with flexible and stretchable substrates: Such as medical-grade films, polydimethylsiloxane (PDMS), polyimide (PI), and thermoplastic polyurethane (TPU). Compatibility with multilayer and hybrid architectures: Facilitating the diverse integration of encapsulating layers, sensing chemicals, and electronics. Because of these benefits, inkjet printing is especially well-suited for wearable health patches, skin electronics, minimally invasive biomedical implants, and point-of-care diagnostics. Core Printed Components Inkjet printing enables the fabrication of diverse device components essential for biomedical monitoring: Electrodes: Usually printed using graphene inks, carbon nanotubes (CNTs), silver nanoparticles (AgNP), gold nanoparticles (AuNP), or conductive polymers like PEDOT:PSS.These electrodes facilitate impedance-based measurements, electrochemical detection, and electrophysiological sensing. Nanotechnology shapes science and technology today[11]. Interconnects: Flexible and mechanically compliant high-conductivity printed traces that connect sensors, antennas, and power management circuits. Due to its flexibility and stretchability, fiber-based wearable electronics hold enormous potential for the next generation of electronics[12]. Antennas: Such as high-frequency radio frequency antennas, resonant LC structures, NFC loops, and inductive coils for wireless power and communication. NFC can operate battery-assisted or batteryless [13]. Biochemical functional layers: Polymer-based recognition elements, ion-selective membranes, printed enzymes, and redox mediators for identifying biomarkers like pH, lactate, glucose, cortisol, and electrolytes. Sweat pH and skin conductivity can indicate metabolic acidosis and autonomic neuropathy, typical consequences of uncontrolled diabetes[14]. Microfluidic structures: Sweat, interstitial fluid, or wound exudate can be directed toward sensing areas using printed channels and fluidic routing layers (including paper-fluidic components). When combined, these elements enable inkjet printing to create intricate, completely integrated biosensing systems without the need for mechanical assembly or conventional photolithography. Inkjet-Printed Biomedical Sensing Modalities Numerous physiological and biochemical sensing domains have made use of inkjet-printed devices, such as: Biochemical sensing: Using printed electrochemical transducers and microfluidic architectures, metabolites (glucose, lactate), hormones (cortisol), electrolytes (Na+, K+), and pH can be detected. As a monosaccharide, glucose is an intermediate product in the metabolic process and a vital energy source[15]. Electrical sensing: ECG, EMG, and EEG measurements enabled by low-impedance printed electrodes that conform intimately to the skin surface. To examine metal film electrode EMG signal performance variables[16]. Physical sensing: Motion, pressure, and strain sensing for posture evaluation, joint monitoring, gait analysis, and rehabilitation. Wearable sensors also track and quantify physical activities like strength training and deteriorated abilities for patients in recovery[17]. Thermal sensing: Distributed resistive temperature detectors and printed thermistors for tracking inflammation and mapping skin temperature in space. Protection, metabolism, control, and feeling are the functions of skin, the biggest organ in the body[18]. Environmental and hydration sensing: Humidity, degree of hydration, moisture content of the wound, and monitoring of the surrounding environment, particularly in clinical wound care and sports performance applications. Physical factors of the wound site are essential indications of wound progression and could inform wound management[19]. Electronics that are inkjet printed naturally mimic the soft, dynamic, and curved shape of human skin and tissues. MPS are advanced in vitro systems that mimic human tissue and organ microenvironments and physiological activities[20].This conformability makes inkjet printing a core platform for future batteryless, wirelessly powered biomedical devices by improving wearer comfort, reducing motion artifacts, improving signal fidelity, and supporting long-term continuous monitoring. 2.2 Wireless Power Transfer Technologies A key factor in creating completely battery-free biomedical equipment, lowering device bulk, increasing mechanical flexibility, and removing the safety concerns related to lithium-based batteries is wireless power transfer, or WPT. WPT guarantees continuous functioning of inkjet-printed sensors while preserving the tiny, soft, and skin-conforming qualities necessary for wearable and implantable applications by supplying power through electromagnetic fields rather than cable connections or onboard storage. Sensors are shrinking, making them lighter and more portable while improving sensitivity, accuracy, and connectivity [21]. Inductive coupling, near-field communication (NFC), radio-frequency (RF) energy harvesting, and hybrid powering techniques are the four main types of WPT technologies utilized in conjunction with inkjet-printed biosensors. Depending on the biomedical application's power needs, operating frequency, transfer efficiency, and allowable distance, each modality has unique benefits and drawbacks. Implantable bioelectronics require wireless power transfer (WPT) for sustained energy without battery life or wires [22]. Inductive Coupling One of the most popular WPT methods for biomedical devices is inductive coupling, which works well in situations when moderate-to-high power is needed over short distances. A wireless power transfer (WPT) technology may alleviate power shortages in implantable medical devices[23]. Key characteristics: Operating frequencies: Usually between 100 kHz and 13.56 MHz, contingent upon the application and coil shape. High power transfer efficiency (PTE): Effective from a few millimeters to a few centimeters away, which makes it perfect for subcutaneous implants, wound monitoring systems, and epidermal sensors. Robust penetration into biological tissue: Stable power delivery for minimally invasive devices is supported by the low attenuation of electromagnetic fields at these frequencies. Thin, soft, and conformal inductively powered biomedical platforms are made possible by the direct integration of printed inductive coils, which are made with PEDOT: PSS or silver nanoparticle inks, onto flexible substrates. Nitrogen plasma from diffuse coplanar surface barrier discharge sintered silver nanoparticles at atmospheric pressure[24]. Near-Field Communication (NFC) NFC allows for simultaneous wireless power and data transfer at the internationally recognized frequency of 13.56 MHz. NFC technology enables short-range, mobile, and wireless communication, triggering the NFC Internal system [25].It is one of the most widely available powering choices for wearable biomedical systems due to its extensive use in consumer electronics, especially smartphones. Key advantages: Dual-function operation: Offers bidirectional data transfer in addition to power supply. User accessibility: Since NFC scanners are built into billions of smartphones, no further specialist equipment is required. Low-voltage, low-power compatibility: Ideal for low-power physiological measurements such as temperature monitoring, skin hydration tracking, and electrochemical sensing. Compact, low-impedance coil designs that provide effective power harvesting from smartphone NFC fields are made possible by the great precision of inkjet-printed NFC antennas. RF Energy Harvesting Electromagnetic energy from far-field radio waves in the UHF and microwave frequency bands is captured by RF energy harvesting. The desire for renewable energy has increased interest in radio frequency (RF) energy harvesting to power wireless devices sustainably[24]. Key characteristics: Longer-range operation: Depending on the transmission power and surrounding conditions, RF signals can be collected at distances ranging from a few millimeters to several meters. Ultra-low-power compatibility: Perfect for devices like intermittent physiological monitoring or passive biochemical sensors that use only μW to mW. Lower harvested power: RF harvesting usually supplies less power than inductive or NFC systems, necessitating extremely effective rectifiers and low-leakage circuits. The integration of radiofrequency harvesting onto ultra-soft, flexible biosensing patches is made possible by rectifying circuits (rectennas) and inkjet-printed antennas. Hybrid Powering Approaches Hybrid powering designs are becoming more popular as a way to get around the drawbacks of particular WPT modalities, like coil misalignment in inductive systems or low collected power in RF systems. These systems come together: Inductive + NFC for near-field reliability, NFC + RF harvesting for adaptive multi-source powering, Solar micro-harvesting + RF/inductive for extended batteryless operation, Multiple resonant coils to maintain power delivery during motion. In real-world biomedical applications, where power efficiency may be weakened by body movement, perspiration, tissue swelling, or device displacement, hybrid systems enhance powering robustness. For next-generation inkjet-printed biomedical sensors, wireless power transmission in all its forms is essential because it allows for seamless integration of ultra-thin, flexible, and skin-like device designs and supports continuous monitoring without the limitations of batteries. 2.3 Biomedical Monitoring Applications Wireless energy-transfer-powered inkjet-printed sensors have shown great promise for a variety of biological monitoring applications. The importance of real-time health monitoring is clear[26]. They are especially well-suited for long-term, practical physiological evaluation because of their inherent softness, conformability, and battery-free operation. Innovative wearable and implantable systems that can continuously collect data in real-time in both clinical and non-clinical situations have been made possible by the combination of printed sensor interfaces with inductive, NFC, or RF-powered architectures. 1. Sweat Biochemistry Monitoring Inkjet-printed microfluidic–electrochemical devices have emerged as a viable platform for noninvasive biochemical investigation, because sweat offers a broad panel of physiological indicators. Recent interest in real-time vital sign monitoring has highlighted biomedical electronics as crucial technology for personal healthcare, medical diagnosis, and sports monitoring[26]. Key advantages: Direct access to metabolites, electrolytes, and hormones Painless and noninvasive sampling High compatibility with skin-mounted flexible electronics Inkjet-printed sweat biosensors have been used to detect: Key electrolytes (Na⁺, K⁺, Cl⁻), Metabolic indicators (lactate, glucose), Hydration markers, Stress biomarkers such as cortisol. Continuous biochemical profiling is made possible by printed microfluidic channels in conjunction with NFC or inductively powered electrochemical sensors, which eliminate the need for large batteries or frequent user intervention. 2. Electrophysiological Monitoring Because of their low interface impedance and conformal contact with the skin, inkjet-printed electrodes made of AgNP, CNT, graphene, or PEDOT:PSS allow for high-fidelity biopotential collection. Applications include: Electrocardiography (ECG): Low-noise cardiac monitoring for stress analysis, long-term heart health, and arrhythmia identification. Electromyography (EMG): Mapping of muscle activity, tracking of therapy, and control of prosthetics. Electroencephalography (EEG): Sleep analysis, seizure detection, and cognitive monitoring. By eliminating the need for battery modules, wireless power transfer (NFC or inductive) enhances comfort and makes it possible for thin, soft patches to be seamlessly integrated into the body. Interfaces made of conductive polymers improve signal stability even more when moving physically. 3. Wound Care and Healing Assessment Noninvasive, continuous monitoring of wound physiology and microenvironment dynamics—critical factors for infection prevention and optimal healing—is provided by inkjet-printed wound monitoring systems. However, physical injury and illnesses can harm the skin, causing functional and structural abnormalities[27]. Monitored parameters include: Moisture levels , guiding dressing changes, pH , indicating infection risk or tissue regeneration stages, Temperature , associated with inflammation or bacterial activity, Biochemical indicators of chronic wound progression. Batteryless wound dressings that offer on-demand or continuous wound status without disturbing the healing tissue are made possible by printed pH sensors, thermistors, and moisture sensors integrated with NFC or inductive coils. 4. Thermal Monitoring Resistive temperature detector (RTD) networks and inkjet-printed thermistors provide high-resolution. The simplicity of the structure and the linear dependence of RTD resistance to temperature have made this temperature sensing technique widely used, especially for high temperatures, where semiconductor-based sensors lack reliability and sensitivity due to NTC-based sensors' exponential nature[27]. Wide-area thermal mapping for uses like: Fever detection, Inflammation characterization, Localized thermal therapy monitoring, Postoperative monitoring and infection prevention. By avoiding the heat and dependability problems that come with conventional battery-powered thermal sensors, these devices benefit from WPT interfaces that enable continuous temperature tracking. 5. Implantable Diagnostics Minimally invasive implanted devices for internal tissue monitoring are made possible by the fabrication of inkjet-printed electronics onto biocompatible substrates. Applications include: Pressure sensors: For keeping an eye on vascular, cerebral, or intra-organ pressure, Strain sensors : For evaluating the biomechanical load on implants, vasculature, or tissues, Biochemical microprobes: For keeping an eye on the tissue microenvironment in specific areas. Because of its wider penetration through biological tissues and excellent power transfer efficiency, inductive coupling is frequently chosen for implanted platforms. 6. Biomechanics and Human Motion Analysis Wearable patches, soft robotic systems, and clothing can all directly include printed strain gauges, flex sensors, and soft deformation sensors. The capacity to monitor tactility, temperature, humidity, and glucose levels has made fibrillar string-based wearable sensors popular in recent years[28]. Biomedical relevance includes: Posture monitoring: Early musculoskeletal disease detection and ergonomic evaluation. Joint angle measurement: Tracking rehabilitation, adjusting gait, and assessing sports performance. Gait analysis: Gait asymmetry monitoring in neurological illnesses and fall risk detection in older populations. These devices are ideal for sports science, clinical rehabilitation, and occupational health monitoring since wireless power transfer guarantees continuous functioning during high mobility. Therefore, a wide and expanding range of physiological measurements are made possible by inkjet-printed, wirelessly driven biomedical devices that combine noninvasive sensing, mechanical comfort, and long-term operational stability. They are positioned as fundamental building blocks for the future of continuous, individualized, and inconspicuous health monitoring due to their adaptability in the biochemical, electrical, thermal, and mechanical domains. 3. Methodology In order to guarantee scientific rigor, reproducibility, and transparency, the methodology of this systematic review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) criteria. seeking new systematic reviews that searched databases, registrations, and other sources[29].A systematic PRISMA-based method was used to find, filter, assess, and synthesize all pertinent literature on wireless power transfer (WPT), biological monitoring, and inkjet-printed electronics. In order to document ten years of significant technological advancements in wearable/implantable biomedical devices, wireless powering modalities, and flexible and printable electronics, a thorough search was carried out from 2015 to 2025. Because of its extensive multidisciplinary coverage in fields such as materials science, additive manufacturing, radio-frequency engineering, and biomedical device research, Google Scholar was chosen as the main database. By choosing peer-reviewed publications that discussed inkjet-printed sensors or electronic structures, included wireless powering (NFC, inductive coupling, RF energy harvesting), and showed promise for biomedical or physiological monitoring, inclusion criteria maintained consistency. Studies that had nothing to do with biomedical sensing, didn't use inkjet printing, had communication-only systems without power transfer, theoretical-only WPT models, and weren't peer-reviewed or written in English were excluded. After eliminating duplicates and unnecessary things, the 2,150 articles that were initially identified were reduced to 1,340. After screening by title and abstract, 220 papers were selected for full-text review. 92 of these researches met all the requirements for inclusion in the final synthesis. The review closely followed the four PRISMA phases—identification, screening, eligibility, and inclusion—to guarantee objectivity and reproducibility. The PRISMA Flow Diagram below provides a summary of the entire process. 3.1 Search Strategy To ensure thorough and reproducible retrieval of all pertinent studies, a systematic Boolean search strategy was used. Boolean operators are recognized by Google Scholar, but field-restricted searches are not supported; as a result, the following search expressions were used: Quotation marks ("…") for exact phrases OR to broaden the search scope Implicit AND (spacing) to combine conceptual groups Parentheses to control logical grouping Four conceptual categories that corresponded to the primary subjects of this review were used to classify search terms: Inkjet / printed electronics Sensors and biosensing modalities Wireless power transfer technologies Biomedical or physiological monitoring To create thorough Boolean search strings, these domains were methodically cross-combined. Table 1. Boolean Logic and Keyword Groups Used in the Search Strategy Concept Group Keywords / Phrases Boolean Structure Example Group 1: Inkjet / Printed Electronics “inkjet printed”, “inkjet printing”, “printed electronics”, “printed sensors”, “additive manufacturing” (“inkjet printed” OR “inkjet printing” OR “printed electronics” OR “printed sensors”) Group 2: Sensors / Biosensing sensor, biosensor, “flexible sensor”, “wearable sensor”, bioelectronics, “biomedical sensor” (sensor OR biosensor OR “flexible sensor” OR “wearable sensor” OR “biomedical sensor”) Group 3: Wireless Power Transfer (WPT) “wireless power transfer”, WPT, “inductive coupling”, “inductive power transfer”, “RF energy harvesting”, “wireless energy harvesting”, “near-field communication”, NFC (“wireless power transfer” OR WPT OR “inductive coupling” OR “RF energy harvesting” OR NFC) Group 4: Biomedical Monitoring “biomedical monitoring”, “health monitoring”, “physiological monitoring”, “medical monitoring”, “wearable health devices” (“biomedical monitoring” OR “health monitoring” OR “physiological monitoring”) 4. Classification Framework A systematic classification framework that arranges ten years of interdisciplinary advancements into logical analytical categories is presented in this review. The methodology is intended to assist researchers in comparing device layouts, identifying technological synergies, and assessing the maturity of combined printed–WPT biomedical systems. In particular, it classifies advancement along four fundamental dimensions: Printed materials and device architectures: Classification of biological, conductive, and dielectric inks; substrate families; multilayer printing techniques; co-fabrication of antennas and sensors; and structural arrangements that allow for biocompatibility, flexibility, and stretchability. A variety of printed flexible electronics materials are also examined[30]. Wireless power delivery strategies: The efficiency, range, integration complexity, and applicability of inductive coupling, NFC-based powering, RF energy harvesting, and hybrid wireless power systems for ultra-low-power biological sensing are all systematically compared. Wireless Power Transfer has the potential to improve sustainability[31]. Biomedical monitoring targets: Physiological domains like biochemical sweat analysis, electrophysiology, wound diagnostics, heat monitoring, hydration tracking, and implantable strain/pressure sensing are mapped to inkjet-printed and wirelessly driven sensors. This unprecedented demand for real-time data and personalized applications has put wearable sensors at the forefront[32]. Hybrid sensor–antenna–power circuits: Finding co-designed electronic architectures that include rectifiers, energy harvesters, printed sensors, on-body antennas, power management circuits, and data interfaces to enable battery-free, small operation suitable for biomedical settings. Flexible substrate energy harvesters are cutting-edge materials, electronics, and renewable energy technologies[33]. This framework supports academic researchers as well as producers of next-generation wearable and implantable healthcare devices by offering a common lens through which technical advancement can be assessed and contrasted. 4. Results and Analysis 4.1 Publication Trends Between 2015 and 2025, there was a noticeable increase in research output, which was indicative of the confluence of wearable healthcare, wireless powering, and additive manufacturing. Several societal and technological factors are responsible for this increase: Maturation of printed functional inks: Printability, conductivity, mechanical compliance, and biocompatibility were all greatly enhanced by developments in carbon-based nanomaterials, conductive polymers (such PEDOT:PSS), and silver nanoparticle (AgNP) formulations. Proliferation of NFC-enabled consumer devices: Research interest was significantly increased by the widespread availability of smartphones with built-in NFC readers, which offered an easily available energy source for batteryless biomedical sensors. Acceleration of wearable healthcare innovations: Flexible, printable sensor technologies are in high demand as wearable, soft electronics gained popularity in applications ranging from sports analytics to personalized medicine. Increased global emphasis on remote and contactless monitoring during the COVID-19 pandemic: Research on lightweight, wireless, and battery-free sensor platforms has significantly increased due to the requirement for continuous, decentralized physiological monitoring. Batteryless, adaptable, and digitally integrated biosensing technologies are becoming increasingly popular, according to the publication trend. 4.2 Inkjet-Printed Materials and Fabrication Insights Through the controlled deposition of conductive, dielectric, and biological inks, inkjet printing makes it possible to create digitally specified, layered biomedical sensors. The materials chosen and how they interact with the substrate have a significant impact on the manufacturing performance. Conductive Materials Silver Nanoparticles (AgNP): Provide the best electrical conductivity of any printable ink, allowing for effective antennas and low-impedance electrodes. However, performance is diminished with mechanical deformation due to intrinsic brittleness and restricted stretchability. PEDOT:PSS: A conductive polymer that is biocompatible, has steady skin-electrode impedance, and is incredibly flexible. Because of its mechanical durability, it is frequently utilized in strain sensors and ECG/EMG electrodes. Carbon Nanotubes (CNTs) and Graphene: Offer adjustable conductivity, enhanced fatigue resistance, and high strain tolerance. These materials show promise for integrated stretchable electronics, soft antennas, and highly bendable sensors. Dielectric Materials & Substrate Considerations Usually, thin, flexible substrates selected for their mechanical, thermal, and chemical qualities are used to construct inkjet-printed devices. Polyethylene Terephthalate (PET), Polyimide (PI): Offer smooth surfaces and dimensional stability; they are ideal for high-resolution printed antennas and interconnects, but they are not stretchy by nature. Polydimethylsiloxane (PDMS), Thermoplastic Polyurethane (TPU): Stretchable, biocompatible, and skin-conformal, making them excellent for epidermal electronics and soft biomedical devices. Surface treatments are frequently necessary to improve ink adherence due to their low surface energy. Cellulose-based Paper Substrates: Provide biodegradability, cheap cost, and inherent compatibility with microfluidics, facilitating point-of-care diagnostics and sweat analysis. Failure Mechanisms in Printed Biomedical Devices The long-term performance of inkjet-printed biological sensors is limited by a number of degradation mechanisms, despite notable advancements: Mechanical cracking under strain >20–30%: When exposed to significant or frequent deformation, conductive traces break, especially with AgNP inks. Adhesion failure in sweat or humid environments: Interlayer adhesion can be compromised by moisture intrusion, particularly in epidermal devices used during physical activity. Thermal mismatch between ink and substrate: Micro-cracking or delamination results from variations in the coefficient of thermal expansion (CTE), which can also create stress accumulation during curing or body temperature oscillations. In practical biomedical applications, these material and fabrication parameters taken together have a direct impact on sensor stability, wireless power harvesting efficiency, and device durability. 4.3 Wireless Power Transfer Integration Inkjet-printed biomedical sensors' functionality, design, and clinical suitability are all significantly influenced by the use of wireless power transfer (WPT) technology. Biosensors are integrated analytical devices containing a recognition element made of physiologically sensitive materials, a physicochemical transducer, and a signal processor [34]. The power levels, operating distances, and form-factor implications of each WPT modality—RF energy harvesting, NFC, and inductive coupling—affect the kinds of sensing tasks that can be dependably handled. Near-Field Communication (NFC) NFC is the most extensively utilized WPT technique in inkjet-printed biomedical systems due to its ubiquity, simplicity, and dual-functionality. Key strengths: Universal compatibility with smartphones: External instrumentation is no longer necessary thanks to NFC-enabled mobile smartphones, which function as both power sources and data readers. Simplified system design: NFC antennas that are inkjet printed require less extra circuitry (rectifiers, regulators), which improves flexibility and thins the device. Ideal for skin-mounted applications: When ultra-low-power electrochemical or temperature sensing is adequate, NFC's modest power output works well for sweat biosensing, wound patches, and epidermal thermal sensors. NFC has emerged as the go-to method for consumer-grade wearable health sensors and point-of-care biomedical diagnostics because of its accessibility and ease of use. Inductive Power Transfer Compared to NFC or RF harvesting, inductive coupling offers a larger power delivery capability, which makes it particularly appropriate for biomedical applications needing steady, uninterrupted power. Key strengths: Supports higher power densities: Able to power microprocessors, sensors, and low-power stimulators or LEDs. Robust tissue penetration: Implantable devices are made possible by the effective penetration of skin and biological tissue by magnetic fields at typical inductive frequencies. Reduced sensitivity to alignment for short distances: Enhances performance in soft-tissue interfaces, subdermal implants, and wound beds. Flexible inductive coils can be made via inkjet printing, which permits conformal integration into epidermal patches, soft implants, and surgical dressings. Thus, this modality is prevalent in deep-tissue physiological probes, subdermal strain monitors, and implanted pressure sensors. RF Energy Harvesting Although RF energy harvesting is appealing for long-range, covert powering, it is limited by incredibly low power availability. Key characteristics: Long-range operation: Low-maintenance, passive biomedical sensing is made possible by the ability to capture radiofrequency signals from a transmitter few centimeters to several meters away. Ultra-low-power operation: Applications are restricted to sensors with modest energy requirements since harvested power usually falls between μW and low mW. Ideal for intermittent or event-driven sensing: Beneficial for biochemical or environmental monitoring when ongoing sampling is not necessary. Lightweight, incredibly flexible ambient-powered biosensors are made possible by inkjet-printed RF antennas and rectennas; nonetheless, power shortage continues to be the fundamental obstacle, limiting the viability of multi-sensor platforms or high-bandwidth electrophysiology. 4.4 Biomedical Applications A wide variety of physiological, biochemical, and clinical monitoring duties are supported by wirelessly powered, inkjet-printed biomedical systems. They are especially well-suited for continuous, noninvasive, and minimally invasive health assessment because of their thin, flexible structures and battery-free operation. The primary application domains found in the literature are compiled in the ensuing subsections. Biochemical Biosensing Electrochemical inks, enzyme layers, and ion-selective membranes can be precisely deposited using inkjet printing. These materials are frequently combined with printed microfluidic channels to provide controlled analyte routing. The following are some common uses for these hybrid microfluidic–electrochemical platforms: Metabolite detection: glucose, lactate Electrolyte monitoring: sodium, potassium, chloride Hormonal biomarkers: cortisol Sweat composition analysis: hydration status, pH, total ionic content NFC-based WPT in conjunction with printed microfluidics enables real-time biochemical measurement and on-demand powering without the need for heavy batteries or inflexible circuitry. Because of this, these devices are especially well-suited for individualized metabolic tracking, occupational health, and sports medicine. Electrophysiology Low skin–electrode impedance and superior conformability to the epidermis are provided by inkjet-printed electrodes made of silver nanoparticle (AgNP) inks, PEDOT:PSS, graphene, or CNT composites. For ink rheology, printing, post-print treatment, and printed electronics device performance, silver nanoparticle (Ag NPs)-based inks must be optimal. This paper summarizes the methods and mechanisms for making highly conductive Ag NPs-based inks under mild sintering settings [23]. These characteristics allow for the steady acquisition of: Electrocardiography (ECG) for cardiac rhythm and stress analysis Electromyography (EMG) for neuromuscular diagnostics and prosthetic control Electroencephalography (EEG) for neurological monitoring and sleep analysis Rigid battery modules are eliminated and mechanical interference is decreased by wireless power connections, including NFC and inductive coupling. In recent years, NFC and RFID technologies were used to study WPT deployment and wireless communication[35].The resulting printed electrophysiological patches are more suitable for wearable health, rehabilitation, and remote patient monitoring because they provide good signal fidelity even during moderate user movements. Wound Monitoring Particularly for chronic and surgical wounds, printed sensors have shown great promise in the management of wound care. Several sensing modalities can be used with inkjet printing to create breathable, soft wound dressings: Moisture and hydration monitoring for optimizing dressing-change schedules pH tracking to detect infection or assess healing progression Temperature sensing to identify localized inflammation Electrochemical markers indicative of infection or tissue degradation Continuous, noninvasive wound observation without disrupting the healing tissue is made possible by batteryless powering via NFC or inductive coils—a significant benefit over conventional assessment methods. Temperature Monitoring High-resolution thermal mapping over the skin or wound surface is made possible by resistive temperature detectors (RTDs) and inkjet-printed thermistors. These sensors facilitate: Monitoring of fever and systemic temperature The identification of inflammation in musculoskeletal injuries Infection-related localized thermal abnormalities Monitoring thermal responses in healing or therapeutic contexts Wireless charging and large-area printed temperature arrays offer tiny, inconspicuous, and cozy substitutes for traditional temperature sensors. Implantable and Minimally Invasive Diagnostics Soft, minimally invasive implantable devices that are charged wirelessly by inductive coupling are made possible by inkjet printing on biocompatible or biodegradable substrates. These systems facilitate: Strain sensing: for keeping an eye on vascular dynamics, organ motility, or tissue stretching Pressure sensing: monitoring of intracranial, intravascular, intra-organ, or subcutaneous pressure Biochemical microprobes: localized perception in organ compartments or tissues Miniaturized implants with mechanical compliance that lessens tissue irritation and increases biostability are made possible by printed inductive coils. These technologies show promise as potential candidates for implantable continuous monitoring platforms of the future. Thus, a wide range of clinical and physiological domains are covered by inkjet-printed, wirelessly powered biomedical devices, showcasing the adaptability and revolutionary potential of additive manufacturing for next-generation healthcare technology. 5. Discussion In the last ten years, there has been a noticeable and quickening trend toward the creation of completely battery-free biomedical monitoring systems through the integration of inkjet printing and wireless power transfer (WPT). Wireless power transfer (WPT) systems are increasingly appropriate for powering complex multifunctional micro-electronic devices like biomedical implants[ 36 ]. Due to its widespread smartphone compatibility and capacity for simultaneous power and data transfer, near-field communication (NFC) has emerged as the most popular WPT modality for skin-worn and sweat-based biosensors. On the other hand, inductive power transfer is still the best choice for deep-tissue and implanted devices, where a stronger magnetic coupling and a larger power capacity are crucial. WPT uses electromagnetic fields to transport power. This technique has far-field and near-field transmission distances. WPT [ 37 ].Longer working distances are possible using radio-frequency (RF) energy harvesting, but its use is constrained by the low harvestable power levels, which are still insufficient for continuous or high-bandwidth sensing applications. The results of this research collectively demonstrate significant advancements in a number of technological pillars, such as the development of multimodal biomedical sensing architectures, flexible antenna–sensor co-design, high-resolution printing, and functional ink composition. Recent studies have reviewed flexible and wearable antenna materials, construction, and applications[ 38 ] .With these advancements, inkjet printing is now positioned as a key enabling technology for ongoing, individualized health monitoring. Nevertheless, despite these developments, a number of unresolved issues still prevent widespread clinical deployment, including mechanical durability under real-world motion, degradation from perspiration and moisture, limited wireless power availability, and the lack of standardized benchmarking or regulatory testing protocols. The important gaps and limits covered in the next part are directly motivated by these enduring constraints. 6. Critical Gaps and Limitations Significant obstacles still exist in the areas of materials, device physics, system integration, and translational preparedness, even in the face of notable advancements in inkjet-printed electronics and wireless power transmission for biomedical monitoring. This review offers a thorough evaluation of these restrictions, emphasizing the shortcomings of the technologies in use today: Mechanical fatigue and structural degradation : Reliability in actual wearable and implantable situations is hampered by the frequent breaking, delamination, resistance drift, or loss of functionality of printed conductive traces and sensing layers during cyclic bending, stretching, perspiration exposure, and prolonged skin adhesion. Reliability is the likelihood that a bioelectronic device will perform as intended over a specific period and under expected operational conditions[ 39 ]. Parasitic losses and limited harvested power : Coil misalignment, electromagnetic detuning, impedance mismatch, and environmental parasites all significantly lower the efficiency of wireless power transfer. For high-bandwidth biomedical applications or multi-sensor applications, RF energy harvesting usually produces power that is insufficient (in the µW–mW range). Energy harvesting, often called energy scavenging, converts environmental energy into electricity [ 40 ]. Biosafety and long-term biocompatibility concerns : Long-term interaction with carbon nanomaterials, printed polymers, and metallic nanoparticles (like AgNP) can cause skin irritation or cytotoxicity. Additional issues with chronic implantation include inflammation, ink residue leaking, and destruction by body fluids. Silver nanoparticles (AgNPs) are popular for their antibacterial and biological characteristics[ 41 ]. Clinical under-validation and limited human studies : Most published systems are only shown in small volunteer studies, brief pilot tests, or benchtop environments. Medical adoption is restricted by the lack of strong clinical trials, long-term evaluations, and regulatory-grade validation. Signal fidelity and susceptibility to noise : Motion artifacts, impedance instability, temperature drift, and electromagnetic interference are all problems that printed sensor systems face.Based on electrical and mechanical properties, it investigates various materials for sensor electrode and substrate development [ 42 ]. Accurate biochemical or electrophysiological signal capture is made more difficult by the numerous noise channels introduced by wireless powering. Lack of standardized testing protocols : For the evaluation of printed WPT-powered biomedical devices, there is no standard framework. Rectenna and power transmission efficiency affect WPT system efficiency[ 43 ]. Cross-study comparison is challenging as translational progress is slowed by variations in ink compositions, printing parameters, power transfer configurations, and biosensing metrics. By methodically recognizing these obstacles, this analysis makes it clear where innovation is most urgently needed and lays the groundwork for future research to focus on batteryless biomedical systems that are clinically viable, dependable, and scalable. 7. Future Research Directions This paper presents a forward-looking path for the creation of next-generation inkjet-printed, wirelessly powered biomedical systems, building on technology advancements and acknowledged constraints. A number of important study paths become apparent: Hybrid multi-method printing strategies : Inkjet printing will be used more often in future devices in conjunction with screen printing, gravure, aerosol jet, extrusion-based, or laser sintering processes. High-performance, multi-material, three-dimensional device architectures that are suited to biomedical requirements can be made possible by this hybrid technique, which can overcome present constraints in resolution, conductivity, multilayer alignment, and stretchability. Biodegradable, biocompatible, and self-healing printed electronics : Transient biomedical implants will be made possible by sustainable printed electronics based on biodegradable substrates (cellulose, silk fibroin, polylactic acid) and environmentally friendly conductive inks. In the meantime, dynamic covalent networks and self-healing polymers offer improved mechanical reliability under cyclic deformation, enhancing durability during actual wear. Ultra-low-power IC and circuit co-integration : Future systems must incorporate ultralow-power ASICs, energy-efficient analog front-ends, and adaptive power management circuits to get around WPT's energy constraints, particularly with regard to RF harvesting. Multi-sensor operation on microwatt-level power budgets will require advancements in passive amplification, near-threshold CMOS computation, and rectifier efficiency optimization. AI-assisted sensing, analytics, and digital health pipelines : Personalized health interventions, motion artifact correction, physiological trend prediction, and signal fidelity enhancement are all made possible by machine learning and artificial intelligence algorithms. Inkjet-printed sensors will become sophisticated, predictive healthcare solutions when AI is integrated at the edge (on-device inference) or through secure cloud pipelines. Clinical translation, standardization, and regulatory frameworks : In order to go from lab prototypes to clinically deployable devices, future research must give priority to longitudinal studies, human subject trials, and medical-grade benchmarks. Regulatory approval and commercial acceptance will be accelerated by standardizing printing parameters, biosensing metrics, wireless power transfer efficiency, safety limitations, and biocompatibility testing. Together, these research avenues pave the way for inkjet-printed biomedical systems that are clinically relevant, scalable, and battery-free. The field is positioned to provide revolutionary solutions for continuous and individualized healthcare monitoring by developing power electronics, fabrication engineering, materials science, and clinical validation. 8. Novelty and Contributions For the first time, this systematic analysis offers a cohesive, ten-year synthesis of the relationship between wireless power transmission and inkjet-printed electronics, particularly for biomedical monitoring applications. Although printed electronics, wearable sensors, and wireless powering have all been explored separately in earlier reviews, none of them have thoroughly combined these fields within a biological setting. The current work makes a number of original contributions: 1. Multi-Domain Integration This review methodically synthesizes developments in the following areas to bring together previously disparate research streams: Inkjet printing materials , such as carbon-based nanomaterials, conductive polymers, and metallic nanoparticles; Functional inks and substrates , covering materials that are biocompatible, stretchy, and flexible; Biochemical and biophysical sensing mechanisms , encompassing mechanical, thermal, electrochemical, and electrophysiological modes; Wireless power transfer mechanisms , including advancements in RF energy harvesting, NFC, and inductive coupling designed for ultra-low-power devices; Wearable and implantable biomedical systems , showcasing device designs that combine WPT with printed sensors for ongoing, battery-free monitoring. Understanding how fabrication technologies, power delivery methods, and biomedical needs come together to provide next-generation health monitoring platforms requires an integrated viewpoint. 9. Conclusion A significant technological advancement in the development of contemporary biomedical monitoring systems is represented by inkjet-printed sensors that are powered by wireless energy transmission. Nowadays, wireless power transfer (WPT) technologies are common[ 44 ].They are positioned as top contenders for next-generation wearable, epidermal, and implantable health technologies due to their intrinsic benefits, which include lightweight structure, mechanical flexibility, low-cost fabrication, digital manufacturability, and the elimination of cumbersome on-board batteries. All of the fundamental pillars of this field—functional ink engineering, substrate optimization, high-resolution additive manufacturing, printed antenna and coil design, and multimodal biomedical sensor integration—have seen significant advancements over the last ten years. Inkjet printing combined with wireless power transfer modalities including NFC, inductive coupling, and RF energy harvesting has enabled a new generation of batteryless platforms for continuous, event-driven, or on-demand physiological monitoring. These integrated devices show promise in biochemical sweat sensing, electrophysiology, wound health evaluation, hydration tracking, temperature mapping, and minimally invasive implanted diagnostics. Ultrathin, conformal, and discreet form factors improve translational potential, therapeutic relevance, and user comfort. In spite of these advances, numerous basic difficulties persist. Long-term deployment is limited by mechanical durability under load, sweat, and constant motion. In RF-harvested systems, wireless power limits operational budgets, sampling rates, and multi-sensor integration. Long-term biosafety concerns with encapsulating materials, polymer additives, and metallic nanoparticle inks require more research. Motion, temperature, and skin–sensor interface changes can impair signal quality. Lack of human-subject studies, clinical workflow integration, and standardized benchmarking remain barriers to regulatory approval and practical implementation. However, emergent innovation avenues provide hope. For complicated, layered designs, hybrid multi-method additive production provides precision and conductivity. Self-healing, biodegradable, and eco-friendly printed materials can extend gadget life and biocompatibility. Ultra-low-power circuit topologies maximize RF-harvested platform viability. AI-enhanced biosignal analytics reduce noise, extract biomarkers, and provide personalized health insights. Multi-modal wireless powering strategies—combining solar microharvesting, inductive, RF, and NFC—may improve operational robustness in varied situations. This systematic study describes how inkjet-printed, wirelessly powered biomedical sensors go from lab prototypes to clinically validated, scalable, and widely adopted healthcare devices. This vision requires coordinated advances in materials science, flexible electronics, wireless power engineering, device packaging, biosignal processing, regulatory science, and human-centered clinical research. Engineering advances, supportive clinical guidelines, regulatory frameworks, and commercialization channels that ensure safe, cheap, and equitable deployment will be needed to integrate these technologies into real-world healthcare. Through interdisciplinary collaboration, inkjet-printed, battery-free biomedical gadgets could revolutionize customized digital health, chronic disease management, and preventative medicine worldwide. Declarations Acknowledgment The authors thank the Department of Computer Science and Engineering at Islamic University, Kushtia, Bangladesh, for its academic and institutional support throughout the development of this study, “Inkjet-Printed Sensors Powered by Wireless Power Transfer for Biomedical Monitoring: A Decade of Evidence — A Systematic Review.” The University of Alabama at Birmingham, Trine University, and Western Illinois University provided scholarly resources, technical support, and a collaborative academic atmosphere that helped the writers complete this work. Funding Declaration No public, commercial, or non-profit grants supported this research. Conflict of Interest The authors declare no financial or personal affiliations that could have influenced this manuscript's findings. References G. 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Meitei, “A Review on Wireless Power Transfer Systems,” in Data Science and Network Engineering , S. Namasudra, N. Kar, S. K. Patra, and D. Taniar, Eds., Singapore: Springer Nature, 2025, pp. 301–312. doi: 10.1007/978-981-97-8336-6_23. Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. 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13:53:43","extension":"html","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":158029,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8464801/v1/96be958f459db0f09f297d2d.html"},{"id":99618773,"identity":"ea3f2a58-9ab8-41ef-b810-29d6b331c0ec","added_by":"auto","created_at":"2026-01-06 13:53:42","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":94639,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePRISMA 2020 Flow Diagram\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-8464801/v1/31b1199baa5af9e64bb854c4.png"},{"id":99793152,"identity":"0eff5e9e-7228-47a2-af76-792d16a857bf","added_by":"auto","created_at":"2026-01-08 13:31:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2731142,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8464801/v1/86a718ba-db87-4aa2-aa4f-60292eb42454.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003eInkjet-Printed Sensors Powered by Wireless Power Transfer for Biomedical Monitoring: A Decade of Evidence — A Systematic Review\u003c/p\u003e","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eOver the past ten years, biomedical sensing technologies have experienced a significant shift due to the emergence of ultrathin, flexible, and skin-conforming devices that can continually monitor physiological data with little effort on the part of the user.\u0026nbsp;Flexible electronics can fit onto any curved surface, such as human skin and organs, without changing their properties, making them suitable for wearable or implantable healthcare and monitoring systems [1].Conventional wearable technology frequently uses battery-operated power modules and stiff electronic components that limit wearability over an extended period of time, impair comfort, and present safety issues in implantable settings. On the other hand, lightweight, mechanically compliant, and geometrically flexible biosensor platforms that naturally interface with the human body are made possible by printed electronics, especially those made by inkjet printing.\u0026nbsp;Electrochemical biosensors are the best for designing and making flexible and wearable sensors due to their convenience, quick response, portability, and natural downsizing\u0026nbsp;[2].\u003c/p\u003e\n\u003cp\u003eDigital pattern programmability, maskless and non-contact deposition, little material waste, quick prototyping, and compatibility with a variety of substrates and functional inks are some of the benefits that inkjet printing offers over conventional microfabrication methods. Finally, inkjet printing reduces manufacturing procedures and setup expenses, making large area sensor fabrication rapid and cost-effective [3].This adaptability makes inkjet printing a crucial enabler for next-generation wearable and epidermal biosensing systems by enabling the quick manufacture of electrodes, interconnects, antennas, microfluidic channels, and biochemical sensing layers.\u0026nbsp;Due to its cost efficiency, mass production, simplicity, and environmental sustainability, flexible sensor technology, notably inkjet printing on flexible substrates, is gaining popularity[4].\u003c/p\u003e\n\u003cp\u003eOne of the most enduring issues in the creation of soft, skin-mounted, or implantable biomedical systems is powering.\u0026nbsp;This study will implement and assess a power device for future integration with an implantable biomedical system [5].Conventional batteries pose concerns such as limited operational lifetime, frequent recharging requirements, mechanical rigidity, physiological incompatibility, possible leakage, increased system thickness, and constraints on physical flexibility. An attractive substitute is wireless power transfer (WPT), which is accomplished by RF energy harvesting, near-field communication (NFC), and inductive coupling. Implanted bioelectronics require wireless power transfer because cable connections are impractical [6]. WPT makes it possible for completely passive, maintenance-free, and mechanically compliant sensor platforms that can run continuously by doing away with the requirement for on-board batteries.\u003cbr\u003e\u0026nbsp;\u003cbr\u003e\u0026nbsp;Research that integrates these fields is still few and dispersed, despite significant developments in materials, printing techniques, antenna design, biosensing techniques, and wireless powering. Existing research often focus on a particular dimension\u0026mdash;such as printing conductive ink patterns, improving antenna designs, or demonstrating novel biochemical sensing modalities\u0026mdash;without offering an integrated, system-level study.\u0026nbsp;Wireless biosensing is important because it can monitor physiological data in real time without wires\u0026nbsp;[7]. The translational potential of fully printed, battery-free biomedical devices is constrained by the lack of a unified knowledge.\u003cbr\u003e\u0026nbsp;\u003cbr\u003e\u0026nbsp;This systematic review addresses this knowledge gap by examining inkjet-printed sensors and wireless power transfer technologies for biomedical monitoring over 10 years.\u0026nbsp;Increasing biological applications require high-portable, low-invasive, real-time, and long-term sensing\u0026nbsp;[8].The review describes the fundamental ideas, new developments in technology, biomedical uses, performance constraints, and new prospects in this multidisciplinary sector. This sensor\u0026apos;s power efficiency, adaptability, and cost effectiveness show that inkjet-printing may create green, high-functioning devices as alternatives to silicon-based methods[9].\u003c/p\u003e\n\u003cp\u003eOur goal is to provide a cohesive framework that facilitates further development of biomedical monitoring systems that are completely battery-free, scalable, and clinically dependable.\u003c/p\u003e"},{"header":"2. Background","content":"\u003ch3\u003e\u003cstrong\u003e2.1 Inkjet-Printed Electronics and Biomedical Sensors\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eOne effective and adaptable additive manufacturing method for creating next-generation biomedical sensors is inkjet printing.\u0026nbsp;Wireless device production and deployment, especially flexible or soft ones, require design, materials, and efficient architectures [10]. It works as a drop-on-demand, digitally controlled deposition method that allows for the accurate application of functional materials, such as conductive, dielectric, or biological ones, onto a variety of surfaces. The sensor converts cardiac vibrations into electrical signals[9].Inkjet printing is particularly appealing for flexible and wearable biomedical applications because it enables quick, maskless patterning with little material consumption, in contrast to classic photolithographic techniques.\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eKey Advantages\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eInkjet printing has a number of advantages that make it a top fabrication technique for soft, conformal biosensing systems:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eMaskless, non-contact patterning:\u003c/strong\u003e Lowers the chance of contamination and gets rid of expensive lithographic stages.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eMinimal material waste (\u0026lt;10%):\u003c/strong\u003e Substantially less than subtractive manufacturing methods.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eRapid design iteration:\u003c/strong\u003e Sensor geometry can be changed almost instantly thanks to digital design.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eHigh printing resolution (down to 20\u0026ndash;50 \u0026mu;m):\u003c/strong\u003e Appropriate for microfluidic features, electrodes, and antennas.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eLow-cost prototyping with scalable manufacturing:\u003c/strong\u003e Suitable for both industrial roll-to-roll processing and laboratory prototyping.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eIntegration with flexible and stretchable substrates:\u003c/strong\u003e Such as medical-grade films, polydimethylsiloxane (PDMS), polyimide (PI), and thermoplastic polyurethane (TPU).\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eCompatibility with multilayer and hybrid architectures:\u003c/strong\u003e Facilitating the diverse integration of encapsulating layers, sensing chemicals, and electronics.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eBecause of these benefits, inkjet printing is especially well-suited for wearable health patches, skin electronics, minimally invasive biomedical implants, and point-of-care diagnostics.\u003c/p\u003e\n\u003ch4\u003e\u003cstrong\u003eCore Printed Components\u003c/strong\u003e\u003c/h4\u003e\n\u003cp\u003eInkjet printing enables the fabrication of diverse device components essential for biomedical monitoring:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eElectrodes:\u003c/strong\u003e Usually printed using graphene inks, carbon nanotubes (CNTs), silver nanoparticles (AgNP), gold nanoparticles (AuNP), or conductive polymers like PEDOT:PSS.These electrodes facilitate impedance-based measurements, electrochemical detection, and electrophysiological sensing. Nanotechnology shapes science and technology today[11].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eInterconnects:\u003c/strong\u003e Flexible and mechanically compliant high-conductivity printed traces that connect sensors, antennas, and power management circuits. Due to its flexibility and stretchability, fiber-based wearable electronics hold enormous potential for the next generation of electronics[12].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eAntennas:\u003c/strong\u003e Such as high-frequency radio frequency antennas, resonant LC structures, NFC loops, and inductive coils for wireless power and communication. NFC can operate battery-assisted or batteryless [13].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eBiochemical functional layers:\u003c/strong\u003e Polymer-based recognition elements, ion-selective membranes, printed enzymes, and redox mediators for identifying biomarkers like pH, lactate, glucose, cortisol, and electrolytes. Sweat pH and skin conductivity can indicate metabolic acidosis and autonomic neuropathy, typical consequences of uncontrolled diabetes[14].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eMicrofluidic structures:\u003c/strong\u003e Sweat, interstitial fluid, or wound exudate can be directed toward sensing areas using printed channels and fluidic routing layers (including paper-fluidic components).\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eWhen combined, these elements enable inkjet printing to create intricate, completely integrated biosensing systems without the need for mechanical assembly or conventional photolithography.\u003c/p\u003e\n\u003ch4\u003eInkjet-Printed Biomedical Sensing Modalities\u003c/h4\u003e\n\u003cp\u003eNumerous physiological and biochemical sensing domains have made use of inkjet-printed devices, such as:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eBiochemical sensing:\u003c/strong\u003e Using printed electrochemical transducers and microfluidic architectures, metabolites (glucose, lactate), hormones (cortisol), electrolytes (Na+, K+), and pH can be detected. As a monosaccharide, glucose is an intermediate product in the metabolic process and a vital energy source[15].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eElectrical sensing:\u003c/strong\u003e ECG, EMG, and EEG measurements enabled by low-impedance printed electrodes that conform intimately to the skin surface. To examine metal film electrode EMG signal performance variables[16].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePhysical sensing:\u003c/strong\u003e Motion, pressure, and strain sensing for posture evaluation, joint monitoring, gait analysis, and rehabilitation. Wearable sensors also track and quantify physical activities like strength training and deteriorated abilities for patients in recovery[17].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eThermal sensing:\u003c/strong\u003e Distributed resistive temperature detectors and printed thermistors for tracking inflammation and mapping skin temperature in space. Protection, metabolism, control, and feeling are the functions of skin, the biggest organ in the body[18].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eEnvironmental and hydration sensing:\u003c/strong\u003e Humidity, degree of hydration, moisture content of the wound, and monitoring of the surrounding environment, particularly in clinical wound care and sports performance applications. Physical factors of the wound site are essential indications of wound progression and could inform wound management[19].\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eElectronics that are inkjet printed naturally mimic the soft, dynamic, and curved shape of human skin and tissues. MPS are advanced in vitro systems that mimic human tissue and organ microenvironments and physiological activities[20].This conformability makes inkjet printing a core platform for future batteryless, wirelessly powered biomedical devices by improving wearer comfort, reducing motion artifacts, improving signal fidelity, and supporting long-term continuous monitoring.\u003c/p\u003e\n\u003ch2\u003e\u003cstrong\u003e2.2 Wireless Power Transfer Technologies\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eA key factor in creating completely battery-free biomedical equipment, lowering device bulk, increasing mechanical flexibility, and removing the safety concerns related to lithium-based batteries is wireless power transfer, or WPT. WPT guarantees continuous functioning of inkjet-printed sensors while preserving the tiny, soft, and skin-conforming qualities necessary for wearable and implantable applications by supplying power through electromagnetic fields rather than cable connections or onboard storage. Sensors are shrinking, making them lighter and more portable while improving sensitivity, accuracy, and connectivity [21].\u003c/p\u003e\n\u003cp\u003eInductive coupling, near-field communication (NFC), radio-frequency (RF) energy harvesting, and hybrid powering techniques are the four main types of WPT technologies utilized in conjunction with inkjet-printed biosensors. Depending on the biomedical application\u0026apos;s power needs, operating frequency, transfer efficiency, and allowable distance, each modality has unique benefits and drawbacks.\u0026nbsp;Implantable bioelectronics require wireless power transfer (WPT) for sustained energy without battery life or wires [22].\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eInductive Coupling\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eOne of the most popular WPT methods for biomedical devices is inductive coupling, which works well in situations when moderate-to-high power is needed over short distances. A wireless power transfer (WPT) technology may alleviate power shortages in implantable medical devices[23].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eKey characteristics:\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eOperating frequencies:\u003c/strong\u003e Usually between 100 kHz and 13.56 MHz, contingent upon the application and coil shape.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eHigh power transfer efficiency (PTE):\u003c/strong\u003e Effective from a few millimeters to a few centimeters away, which makes it perfect for subcutaneous implants, wound monitoring systems, and epidermal sensors.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eRobust penetration into biological tissue:\u003c/strong\u003e Stable power delivery for minimally invasive devices is supported by the low attenuation of electromagnetic fields at these frequencies.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThin, soft, and conformal inductively powered biomedical platforms are made possible by the direct integration of printed inductive coils, which are made with PEDOT: PSS or silver nanoparticle inks, onto flexible substrates.\u0026nbsp;Nitrogen plasma from diffuse coplanar surface barrier discharge sintered silver nanoparticles at atmospheric pressure[24].\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eNear-Field Communication (NFC)\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eNFC allows for simultaneous wireless power and data transfer at the internationally recognized frequency of 13.56 MHz.\u0026nbsp;NFC technology enables short-range, mobile, and wireless communication, triggering the NFC Internal system [25].It is one of the most widely available powering choices for wearable biomedical systems due to its extensive use in consumer electronics, especially smartphones.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eKey advantages:\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eDual-function operation:\u003c/strong\u003e Offers bidirectional data transfer in addition to power supply.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eUser accessibility:\u0026nbsp;\u003c/strong\u003eSince NFC scanners are built into billions of smartphones, no further specialist equipment is required.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eLow-voltage, low-power compatibility:\u003c/strong\u003e Ideal for low-power physiological measurements such as temperature monitoring, skin hydration tracking, and electrochemical sensing.\u0026nbsp;\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eCompact, low-impedance coil designs that provide effective power harvesting from smartphone NFC fields are made possible by the great precision of inkjet-printed NFC antennas.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eRF Energy Harvesting\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eElectromagnetic energy from far-field radio waves in the UHF and microwave frequency bands is captured by RF energy harvesting.\u0026nbsp;The desire for renewable energy has increased interest in radio frequency (RF) energy harvesting to power wireless devices sustainably[24].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eKey characteristics:\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eLonger-range operation:\u003c/strong\u003e Depending on the transmission power and surrounding conditions, RF signals can be collected at distances ranging from a few millimeters to several meters.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eUltra-low-power compatibility:\u003c/strong\u003e Perfect for devices like intermittent physiological monitoring or passive biochemical sensors that use only \u0026mu;W to mW.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eLower harvested power:\u003c/strong\u003e RF harvesting usually supplies less power than inductive or NFC systems, necessitating extremely effective rectifiers and low-leakage circuits.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThe integration of radiofrequency harvesting onto ultra-soft, flexible biosensing patches is made possible by rectifying circuits (rectennas) and inkjet-printed antennas.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eHybrid Powering Approaches\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eHybrid powering designs are becoming more popular as a way to get around the drawbacks of particular WPT modalities, like coil misalignment in inductive systems or low collected power in RF systems. These systems come together:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eInductive + NFC\u003c/strong\u003e for near-field reliability,\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eNFC + RF harvesting\u003c/strong\u003e for adaptive multi-source powering,\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eSolar micro-harvesting + RF/inductive\u003c/strong\u003e for extended batteryless operation,\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eMultiple resonant coils\u003c/strong\u003e to maintain power delivery during motion.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIn real-world biomedical applications, where power efficiency may be weakened by body movement, perspiration, tissue swelling, or device displacement, hybrid systems enhance powering robustness.\u003c/p\u003e\n\u003cp\u003eFor next-generation inkjet-printed biomedical sensors, wireless power transmission in all its forms is essential because it allows for seamless integration of ultra-thin, flexible, and skin-like device designs and supports continuous monitoring without the limitations of batteries.\u003c/p\u003e\n\u003ch2\u003e\u003cstrong\u003e2.3 Biomedical Monitoring Applications\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eWireless energy-transfer-powered inkjet-printed sensors have shown great promise for a variety of biological monitoring applications.\u0026nbsp;The importance of real-time health monitoring is clear[26]. They are especially well-suited for long-term, practical physiological evaluation because of their inherent softness, conformability, and battery-free operation. Innovative wearable and implantable systems that can continuously collect data in real-time in both clinical and non-clinical situations have been made possible by the combination of printed sensor interfaces with inductive, NFC, or RF-powered architectures.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003e1. Sweat Biochemistry Monitoring\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eInkjet-printed microfluidic\u0026ndash;electrochemical devices have emerged as a viable platform for noninvasive biochemical investigation, because sweat offers a broad panel of physiological indicators.\u0026nbsp;Recent interest in real-time vital sign monitoring has highlighted biomedical electronics as crucial technology for personal healthcare, medical diagnosis, and sports monitoring[26].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eKey advantages:\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eDirect access to metabolites, electrolytes, and hormones\u003c/li\u003e\n \u003cli\u003ePainless and noninvasive sampling\u003c/li\u003e\n \u003cli\u003eHigh compatibility with skin-mounted flexible electronics\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eInkjet-printed sweat biosensors have been used to detect:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eKey electrolytes (Na⁺, K⁺, Cl⁻),\u003c/li\u003e\n \u003cli\u003eMetabolic indicators (lactate, glucose),\u003c/li\u003e\n \u003cli\u003eHydration markers,\u003c/li\u003e\n \u003cli\u003eStress biomarkers such as cortisol.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eContinuous biochemical profiling is made possible by printed microfluidic channels in conjunction with NFC or inductively powered electrochemical sensors, which eliminate the need for large batteries or frequent user intervention.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003e2. Electrophysiological Monitoring\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eBecause of their low interface impedance and conformal contact with the skin, inkjet-printed electrodes made of AgNP, CNT, graphene, or PEDOT:PSS allow for high-fidelity biopotential collection.\u003c/p\u003e\n\u003cp\u003eApplications include:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eElectrocardiography (ECG):\u0026nbsp;\u003c/strong\u003eLow-noise cardiac monitoring for stress analysis, long-term heart health, and arrhythmia identification.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eElectromyography (EMG):\u003c/strong\u003e Mapping of muscle activity, tracking of therapy, and control of prosthetics.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eElectroencephalography (EEG):\u003c/strong\u003e Sleep analysis, seizure detection, and cognitive monitoring.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eBy eliminating the need for battery modules, wireless power transfer (NFC or inductive) enhances comfort and makes it possible for thin, soft patches to be seamlessly integrated into the body. Interfaces made of conductive polymers improve signal stability even more when moving physically.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003e3. Wound Care and Healing Assessment\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eNoninvasive, continuous monitoring of wound physiology and microenvironment dynamics\u0026mdash;critical factors for infection prevention and optimal healing\u0026mdash;is provided by inkjet-printed wound monitoring systems. However, physical injury and illnesses can harm the skin, causing functional and structural abnormalities[27].\u003c/p\u003e\n\u003cp\u003eMonitored parameters include:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eMoisture levels\u003c/strong\u003e, guiding dressing changes,\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003epH\u003c/strong\u003e, indicating infection risk or tissue regeneration stages,\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eTemperature\u003c/strong\u003e, associated with inflammation or bacterial activity,\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eBiochemical indicators\u003c/strong\u003e of chronic wound progression.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eBatteryless wound dressings that offer on-demand or continuous wound status without disturbing the healing tissue are made possible by printed pH sensors, thermistors, and moisture sensors integrated with NFC or inductive coils.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003e4. Thermal Monitoring\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eResistive temperature detector (RTD) networks and inkjet-printed thermistors provide high-resolution.\u0026nbsp;The simplicity of the structure and the linear dependence of RTD resistance to temperature have made this temperature sensing technique widely used, especially for high temperatures, where semiconductor-based sensors lack reliability and sensitivity due to NTC-based sensors\u0026apos; exponential nature[27]. Wide-area thermal mapping for uses like:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eFever detection,\u003c/li\u003e\n \u003cli\u003eInflammation characterization,\u003c/li\u003e\n \u003cli\u003eLocalized thermal therapy monitoring,\u003c/li\u003e\n \u003cli\u003ePostoperative monitoring and infection prevention.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eBy avoiding the heat and dependability problems that come with conventional battery-powered thermal sensors, these devices benefit from WPT interfaces that enable continuous temperature tracking.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003e5. Implantable Diagnostics\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eMinimally invasive implanted devices for internal tissue monitoring are made possible by the fabrication of inkjet-printed electronics onto biocompatible substrates.\u0026nbsp;Applications include:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003ePressure sensors:\u0026nbsp;\u003c/strong\u003e For keeping an eye on vascular, cerebral, or intra-organ pressure,\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eStrain sensors :\u003c/strong\u003e For evaluating the biomechanical load on implants, vasculature, or tissues,\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eBiochemical microprobes:\u003c/strong\u003e For keeping an eye on the tissue microenvironment in specific areas.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eBecause of its wider penetration through biological tissues and excellent power transfer efficiency, inductive coupling is frequently chosen for implanted platforms.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003e6. Biomechanics and Human Motion Analysis\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eWearable patches, soft robotic systems, and clothing can all directly include printed strain gauges, flex sensors, and soft deformation sensors.\u0026nbsp;The capacity to monitor tactility, temperature, humidity, and glucose levels has made fibrillar string-based wearable sensors popular in recent years[28].\u0026nbsp;Biomedical relevance includes:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003ePosture monitoring:\u003c/strong\u003e Early musculoskeletal disease detection and ergonomic evaluation.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eJoint angle measurement:\u0026nbsp;\u003c/strong\u003eTracking rehabilitation, adjusting gait, and assessing sports performance.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eGait analysis:\u003c/strong\u003e Gait asymmetry monitoring in neurological illnesses and fall risk detection in older populations.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThese devices are ideal for sports science, clinical rehabilitation, and occupational health monitoring since wireless power transfer guarantees continuous functioning during high mobility.\u003c/p\u003e\n\u003cp\u003eTherefore, a wide and expanding range of physiological measurements are made possible by inkjet-printed, wirelessly driven biomedical devices that combine noninvasive sensing, mechanical comfort, and long-term operational stability. They are positioned as fundamental building blocks for the future of continuous, individualized, and inconspicuous health monitoring due to their adaptability in the biochemical, electrical, thermal, and mechanical domains.\u003c/p\u003e"},{"header":"3. Methodology","content":"\u003cp\u003eIn order to guarantee scientific rigor, reproducibility, and transparency, the methodology of this systematic review adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA 2020) criteria.\u0026nbsp;seeking new systematic reviews that searched databases, registrations, and other sources[29].A systematic PRISMA-based method was used to find, filter, assess, and synthesize all pertinent literature on wireless power transfer (WPT), biological monitoring, and inkjet-printed electronics.\u003c/p\u003e\n\u003cp\u003eIn order to document ten years of significant technological advancements in wearable/implantable biomedical devices, wireless powering modalities, and flexible and printable electronics, a thorough search was carried out from 2015 to 2025. Because of its extensive multidisciplinary coverage in fields such as materials science, additive manufacturing, radio-frequency engineering, and biomedical device research, Google Scholar was chosen as the main database.\u003c/p\u003e\n\u003cp\u003eBy choosing peer-reviewed publications that discussed inkjet-printed sensors or electronic structures, included wireless powering (NFC, inductive coupling, RF energy harvesting), and showed promise for biomedical or physiological monitoring, inclusion criteria maintained consistency. Studies that had nothing to do with biomedical sensing, didn\u0026apos;t use inkjet printing, had communication-only systems without power transfer, theoretical-only WPT models, and weren\u0026apos;t peer-reviewed or written in English were excluded.\u003c/p\u003e\n\u003cp\u003eAfter eliminating duplicates and unnecessary things, the 2,150 articles that were initially identified were reduced to 1,340. After screening by title and abstract, 220 papers were selected for full-text review. 92 of these researches met all the requirements for inclusion in the final synthesis.\u003c/p\u003e\n\u003cp\u003eThe review closely followed the four PRISMA phases\u0026mdash;identification, screening, eligibility, and inclusion\u0026mdash;to guarantee objectivity and reproducibility. The PRISMA Flow Diagram below provides a summary of the entire process.\u003c/p\u003e\n\u003ch2\u003e\u003cstrong\u003e3.1 Search Strategy\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eTo ensure thorough and reproducible retrieval of all pertinent studies, a systematic Boolean search strategy was used. Boolean operators are recognized by Google Scholar, but field-restricted searches are not supported; as a result, the following search expressions were used:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eQuotation marks (\u0026quot;\u0026hellip;\u0026quot;)\u003c/strong\u003e for exact phrases\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eOR\u003c/strong\u003e to broaden the search scope\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eImplicit AND (spacing)\u003c/strong\u003e to combine conceptual groups\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eParentheses\u003c/strong\u003e to control logical grouping\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eFour conceptual categories that corresponded to the primary subjects of this review were used to classify search terms:\u003c/p\u003e\n\u003col\u003e\n \u003cli\u003eInkjet / printed electronics\u003c/li\u003e\n \u003cli\u003eSensors and biosensing modalities\u003c/li\u003e\n \u003cli\u003eWireless power transfer technologies\u003c/li\u003e\n \u003cli\u003eBiomedical or physiological monitoring\u003c/li\u003e\n\u003c/ol\u003e\n\u003cp\u003eTo create thorough Boolean search strings, these domains were methodically cross-combined.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTable 1. Boolean Logic and Keyword Groups Used in the Search Strategy\u003c/strong\u003e\u003c/h3\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 127px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eConcept Group\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 300px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eKeywords / Phrases\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 204px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eBoolean Structure Example\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 127px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 1: Inkjet / Printed Electronics\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 300px;\"\u003e\n \u003cp\u003e\u0026ldquo;inkjet printed\u0026rdquo;, \u0026ldquo;inkjet printing\u0026rdquo;, \u0026ldquo;printed electronics\u0026rdquo;, \u0026ldquo;printed sensors\u0026rdquo;, \u0026ldquo;additive manufacturing\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 204px;\"\u003e\n \u003cp\u003e(\u0026ldquo;inkjet printed\u0026rdquo; OR \u0026ldquo;inkjet printing\u0026rdquo; OR \u0026ldquo;printed electronics\u0026rdquo; OR \u0026ldquo;printed sensors\u0026rdquo;)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 127px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 2: Sensors / Biosensing\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 300px;\"\u003e\n \u003cp\u003esensor, biosensor, \u0026ldquo;flexible sensor\u0026rdquo;, \u0026ldquo;wearable sensor\u0026rdquo;, bioelectronics, \u0026ldquo;biomedical sensor\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 204px;\"\u003e\n \u003cp\u003e(sensor OR biosensor OR \u0026ldquo;flexible sensor\u0026rdquo; OR \u0026ldquo;wearable sensor\u0026rdquo; OR \u0026ldquo;biomedical sensor\u0026rdquo;)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 127px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 3: Wireless Power Transfer (WPT)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 300px;\"\u003e\n \u003cp\u003e\u0026ldquo;wireless power transfer\u0026rdquo;, WPT, \u0026ldquo;inductive coupling\u0026rdquo;, \u0026ldquo;inductive power transfer\u0026rdquo;, \u0026ldquo;RF energy harvesting\u0026rdquo;, \u0026ldquo;wireless energy harvesting\u0026rdquo;, \u0026ldquo;near-field communication\u0026rdquo;, NFC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 204px;\"\u003e\n \u003cp\u003e(\u0026ldquo;wireless power transfer\u0026rdquo; OR WPT OR \u0026ldquo;inductive coupling\u0026rdquo; OR \u0026ldquo;RF energy harvesting\u0026rdquo; OR NFC)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 127px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 4: Biomedical Monitoring\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 300px;\"\u003e\n \u003cp\u003e\u0026ldquo;biomedical monitoring\u0026rdquo;, \u0026ldquo;health monitoring\u0026rdquo;, \u0026ldquo;physiological monitoring\u0026rdquo;, \u0026ldquo;medical monitoring\u0026rdquo;, \u0026ldquo;wearable health devices\u0026rdquo;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 204px;\"\u003e\n \u003cp\u003e(\u0026ldquo;biomedical monitoring\u0026rdquo; OR \u0026ldquo;health monitoring\u0026rdquo; OR \u0026ldquo;physiological monitoring\u0026rdquo;)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003ch2\u003e\u003cstrong\u003e4.\u0026nbsp;\u003c/strong\u003eClassification Framework\u003c/h2\u003e\n\u003cp\u003eA systematic classification framework that arranges ten years of interdisciplinary advancements into logical analytical categories is presented in this review. The methodology is intended to assist researchers in comparing device layouts, identifying technological synergies, and assessing the maturity of combined printed\u0026ndash;WPT biomedical systems. In particular, it classifies advancement along four fundamental dimensions:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003ePrinted materials and device architectures:\u003c/strong\u003e Classification of biological, conductive, and dielectric inks; substrate families; multilayer printing techniques; co-fabrication of antennas and sensors; and structural arrangements that allow for biocompatibility, flexibility, and stretchability. A variety of printed flexible electronics materials are also examined[30].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eWireless power delivery strategies:\u003c/strong\u003e The efficiency, range, integration complexity, and applicability of inductive coupling, NFC-based powering, RF energy harvesting, and hybrid wireless power systems for ultra-low-power biological sensing are all systematically compared. Wireless Power Transfer has the potential to improve sustainability[31].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eBiomedical monitoring targets:\u003c/strong\u003e Physiological domains like biochemical sweat analysis, electrophysiology, wound diagnostics, heat monitoring, hydration tracking, and implantable strain/pressure sensing are mapped to inkjet-printed and wirelessly driven sensors. This unprecedented demand for real-time data and personalized applications has put wearable sensors at the forefront[32].\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eHybrid sensor\u0026ndash;antenna\u0026ndash;power circuits:\u003c/strong\u003e Finding co-designed electronic architectures that include rectifiers, energy harvesters, printed sensors, on-body antennas, power management circuits, and data interfaces to enable battery-free, small operation suitable for biomedical settings. Flexible substrate energy harvesters are cutting-edge materials, electronics, and renewable energy technologies[33].\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eThis framework supports academic researchers as well as producers of next-generation wearable and implantable healthcare devices by offering a common lens through which technical advancement can be assessed and contrasted.\u003c/p\u003e"},{"header":"4. Results and Analysis","content":"\u003ch2\u003e\u003cstrong\u003e4.1 Publication Trends\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eBetween 2015 and 2025, there was a noticeable increase in research output, which was indicative of the confluence of wearable healthcare, wireless powering, and additive manufacturing. Several societal and technological factors are responsible for this increase:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eMaturation of printed functional inks:\u003c/strong\u003e Printability, conductivity, mechanical compliance, and biocompatibility were all greatly enhanced by developments in carbon-based nanomaterials, conductive polymers (such PEDOT:PSS), and silver nanoparticle (AgNP) formulations.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eProliferation of NFC-enabled consumer devices:\u003c/strong\u003e Research interest was significantly increased by the widespread availability of smartphones with built-in NFC readers, which offered an easily available energy source for batteryless biomedical sensors.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eAcceleration of wearable healthcare innovations:\u003c/strong\u003e Flexible, printable sensor technologies are in high demand as wearable, soft electronics gained popularity in applications ranging from sports analytics to personalized medicine.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eIncreased global emphasis on remote and contactless monitoring during the COVID-19 pandemic:\u003c/strong\u003e Research on lightweight, wireless, and battery-free sensor platforms has significantly increased due to the requirement for continuous, decentralized physiological monitoring.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eBatteryless, adaptable, and digitally integrated biosensing technologies are becoming increasingly popular, according to the publication trend.\u003c/p\u003e\n\u003ch2\u003e\u003cstrong\u003e4.2 Inkjet-Printed Materials and Fabrication Insights\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eThrough the controlled deposition of conductive, dielectric, and biological inks, inkjet printing makes it possible to create digitally specified, layered biomedical sensors. The materials chosen and how they interact with the substrate have a significant impact on the manufacturing performance.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eConductive Materials\u003c/strong\u003e\u003c/h3\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eSilver Nanoparticles (AgNP):\u003c/strong\u003e Provide the best electrical conductivity of any printable ink, allowing for effective antennas and low-impedance electrodes. However, performance is diminished with mechanical deformation due to intrinsic brittleness and restricted stretchability.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePEDOT:PSS:\u003c/strong\u003e A conductive polymer that is biocompatible, has steady skin-electrode impedance, and is incredibly flexible. Because of its mechanical durability, it is frequently utilized in strain sensors and ECG/EMG electrodes.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eCarbon Nanotubes (CNTs) and Graphene:\u003c/strong\u003e Offer adjustable conductivity, enhanced fatigue resistance, and high strain tolerance. These materials show promise for integrated stretchable electronics, soft antennas, and highly bendable sensors.\u003c/li\u003e\n\u003c/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eDielectric Materials \u0026amp; Substrate Considerations\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eUsually, thin, flexible substrates selected for their mechanical, thermal, and chemical qualities are used to construct inkjet-printed devices.\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003ePolyethylene Terephthalate (PET), Polyimide (PI):\u003c/strong\u003e Offer smooth surfaces and dimensional stability; they are ideal for high-resolution printed antennas and interconnects, but they are not stretchy by nature.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePolydimethylsiloxane (PDMS), Thermoplastic Polyurethane (TPU):\u003c/strong\u003e Stretchable, biocompatible, and skin-conformal, making them excellent for epidermal electronics and soft biomedical devices. Surface treatments are frequently necessary to improve ink adherence due to their low surface energy.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eCellulose-based Paper Substrates:\u003c/strong\u003e Provide biodegradability, cheap cost, and inherent compatibility with microfluidics, facilitating point-of-care diagnostics and sweat analysis.\u003c/li\u003e\n\u003c/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eFailure Mechanisms in Printed Biomedical Devices\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThe long-term performance of inkjet-printed biological sensors is limited by a number of degradation mechanisms, despite notable advancements:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eMechanical cracking under strain \u0026gt;20\u0026ndash;30%:\u003c/strong\u003e When exposed to significant or frequent deformation, conductive traces break, especially with AgNP inks.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eAdhesion failure in sweat or humid environments:\u003c/strong\u003e Interlayer adhesion can be compromised by moisture intrusion, particularly in epidermal devices used during physical activity.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eThermal mismatch between ink and substrate:\u003c/strong\u003e Micro-cracking or delamination results from variations in the coefficient of thermal expansion (CTE), which can also create stress accumulation during curing or body temperature oscillations.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIn practical biomedical applications, these material and fabrication parameters taken together have a direct impact on sensor stability, wireless power harvesting efficiency, and device durability.\u003c/p\u003e\n\u003ch2\u003e\u003cstrong\u003e4.3 Wireless Power Transfer Integration\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eInkjet-printed biomedical sensors\u0026apos; functionality, design, and clinical suitability are all significantly influenced by the use of wireless power transfer (WPT) technology.\u0026nbsp;Biosensors are integrated analytical devices containing a recognition element made of physiologically sensitive materials, a physicochemical transducer, and a signal processor [34]. The power levels, operating distances, and form-factor implications of each WPT modality\u0026mdash;RF energy harvesting, NFC, and inductive coupling\u0026mdash;affect the kinds of sensing tasks that can be dependably handled.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eNear-Field Communication (NFC)\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eNFC is the most extensively utilized WPT technique in inkjet-printed biomedical systems due to its ubiquity, simplicity, and dual-functionality.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eKey strengths:\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eUniversal compatibility with smartphones:\u003c/strong\u003e External instrumentation is no longer necessary thanks to NFC-enabled mobile smartphones, which function as both power sources and data readers.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eSimplified system design:\u003c/strong\u003e NFC antennas that are inkjet printed require less extra circuitry (rectifiers, regulators), which improves flexibility and thins the device.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eIdeal for skin-mounted applications:\u003c/strong\u003e When ultra-low-power electrochemical or temperature sensing is adequate, NFC\u0026apos;s modest power output works well for sweat biosensing, wound patches, and epidermal thermal sensors.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eNFC has emerged as the go-to method for consumer-grade wearable health sensors and point-of-care biomedical diagnostics because of its accessibility and ease of use.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eInductive Power Transfer\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eCompared to NFC or RF harvesting, inductive coupling offers a larger power delivery capability, which makes it particularly appropriate for biomedical applications needing steady, uninterrupted power.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eKey strengths:\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eSupports higher power densities:\u003c/strong\u003e Able to power microprocessors, sensors, and low-power stimulators or LEDs.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eRobust tissue penetration:\u003c/strong\u003e Implantable devices are made possible by the effective penetration of skin and biological tissue by magnetic fields at typical inductive frequencies.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eReduced sensitivity to alignment for short distances:\u003c/strong\u003e Enhances performance in soft-tissue interfaces, subdermal implants, and wound beds.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eFlexible inductive coils can be made via inkjet printing, which permits conformal integration into epidermal patches, soft implants, and surgical dressings. Thus, this modality is prevalent in deep-tissue physiological probes, subdermal strain monitors, and implanted pressure sensors.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eRF Energy Harvesting\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eAlthough RF energy harvesting is appealing for long-range, covert powering, it is limited by incredibly low power availability.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eKey characteristics:\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eLong-range operation:\u003c/strong\u003e Low-maintenance, passive biomedical sensing is made possible by the ability to capture radiofrequency signals from a transmitter few centimeters to several meters away.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eUltra-low-power operation:\u003c/strong\u003e Applications are restricted to sensors with modest energy requirements since harvested power usually falls between \u0026mu;W and low mW.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eIdeal for intermittent or event-driven sensing:\u003c/strong\u003e Beneficial for biochemical or environmental monitoring when ongoing sampling is not necessary.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eLightweight, incredibly flexible ambient-powered biosensors are made possible by inkjet-printed RF antennas and rectennas; nonetheless, power shortage continues to be the fundamental obstacle, limiting the viability of multi-sensor platforms or high-bandwidth electrophysiology.\u003c/p\u003e\n\u003ch2\u003e\u003cstrong\u003e4.4 Biomedical Applications\u003c/strong\u003e\u003c/h2\u003e\n\u003cp\u003eA wide variety of physiological, biochemical, and clinical monitoring duties are supported by wirelessly powered, inkjet-printed biomedical systems. They are especially well-suited for continuous, noninvasive, and minimally invasive health assessment because of their thin, flexible structures and battery-free operation. The primary application domains found in the literature are compiled in the ensuing subsections.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eBiochemical Biosensing\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eElectrochemical inks, enzyme layers, and ion-selective membranes can be precisely deposited using inkjet printing. These materials are frequently combined with printed microfluidic channels to provide controlled analyte routing. The following are some common uses for these hybrid microfluidic\u0026ndash;electrochemical platforms:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eMetabolite detection:\u003c/strong\u003e glucose, lactate\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eElectrolyte monitoring:\u003c/strong\u003e sodium, potassium, chloride\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eHormonal biomarkers:\u003c/strong\u003e cortisol\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eSweat composition analysis:\u003c/strong\u003e hydration status, pH, total ionic content\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eNFC-based WPT in conjunction with printed microfluidics enables real-time biochemical measurement and on-demand powering without the need for heavy batteries or inflexible circuitry. Because of this, these devices are especially well-suited for individualized metabolic tracking, occupational health, and sports medicine.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eElectrophysiology\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eLow skin\u0026ndash;electrode impedance and superior conformability to the epidermis are provided by inkjet-printed electrodes made of silver nanoparticle (AgNP) inks, PEDOT:PSS, graphene, or CNT composites. For ink rheology, printing, post-print treatment, and printed electronics device performance, silver nanoparticle (Ag NPs)-based inks must be optimal. This paper summarizes the methods and mechanisms for making highly conductive Ag NPs-based inks under mild sintering settings [23].\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;These characteristics allow for the steady acquisition of:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eElectrocardiography (ECG)\u003c/strong\u003e for cardiac rhythm and stress analysis\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eElectromyography (EMG)\u003c/strong\u003e for neuromuscular diagnostics and prosthetic control\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eElectroencephalography (EEG)\u003c/strong\u003e for neurological monitoring and sleep analysis\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eRigid battery modules are eliminated and mechanical interference is decreased by wireless power connections, including NFC and inductive coupling. In recent years, NFC and RFID technologies were used to study WPT deployment and wireless communication[35].The resulting printed electrophysiological patches are more suitable for wearable health, rehabilitation, and remote patient monitoring because they provide good signal fidelity even during moderate user movements.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eWound Monitoring\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eParticularly for chronic and surgical wounds, printed sensors have shown great promise in the management of wound care. Several sensing modalities can be used with inkjet printing to create breathable, soft wound dressings:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eMoisture and hydration monitoring\u003c/strong\u003e for optimizing dressing-change schedules\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003epH tracking\u003c/strong\u003e to detect infection or assess healing progression\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eTemperature sensing\u003c/strong\u003e to identify localized inflammation\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eElectrochemical markers\u003c/strong\u003e indicative of infection or tissue degradation\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eContinuous, noninvasive wound observation without disrupting the healing tissue is made possible by batteryless powering via NFC or inductive coils\u0026mdash;a significant benefit over conventional assessment methods.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eTemperature Monitoring\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eHigh-resolution thermal mapping over the skin or wound surface is made possible by resistive temperature detectors (RTDs) and inkjet-printed thermistors. These sensors facilitate:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eMonitoring of fever and systemic temperature\u003c/li\u003e\n \u003cli\u003eThe identification of inflammation in musculoskeletal injuries\u003c/li\u003e\n \u003cli\u003eInfection-related localized thermal abnormalities\u003c/li\u003e\n \u003cli\u003eMonitoring thermal responses in healing or therapeutic contexts\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eWireless charging and large-area printed temperature arrays offer tiny, inconspicuous, and cozy substitutes for traditional temperature sensors.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eImplantable and Minimally Invasive Diagnostics\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eSoft, minimally invasive implantable devices that are charged wirelessly by inductive coupling are made possible by inkjet printing on biocompatible or biodegradable substrates. These systems facilitate:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eStrain sensing:\u003c/strong\u003e for keeping an eye on vascular dynamics, organ motility, or tissue stretching\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003ePressure sensing:\u003c/strong\u003e monitoring of intracranial, intravascular, intra-organ, or subcutaneous pressure\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eBiochemical microprobes:\u003c/strong\u003e localized perception in organ compartments or tissues\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eMiniaturized implants with mechanical compliance that lessens tissue irritation and increases biostability are made possible by printed inductive coils. These technologies show promise as potential candidates for implantable continuous monitoring platforms of the future.\u003c/p\u003e\n\u003cp\u003eThus, a wide range of clinical and physiological domains are covered by inkjet-printed, wirelessly powered biomedical devices, showcasing the adaptability and revolutionary potential of additive manufacturing for next-generation healthcare technology.\u003c/p\u003e"},{"header":"5. Discussion","content":"\u003cp\u003eIn the last ten years, there has been a noticeable and quickening trend toward the creation of completely battery-free biomedical monitoring systems through the integration of inkjet printing and wireless power transfer (WPT). Wireless power transfer (WPT) systems are increasingly appropriate for powering complex multifunctional micro-electronic devices like biomedical implants[\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. Due to its widespread smartphone compatibility and capacity for simultaneous power and data transfer, near-field communication (NFC) has emerged as the most popular WPT modality for skin-worn and sweat-based biosensors. On the other hand, inductive power transfer is still the best choice for deep-tissue and implanted devices, where a stronger magnetic coupling and a larger power capacity are crucial. WPT uses electromagnetic fields to transport power. This technique has far-field and near-field transmission distances. WPT [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e].Longer working distances are possible using radio-frequency (RF) energy harvesting, but its use is constrained by the low harvestable power levels, which are still insufficient for continuous or high-bandwidth sensing applications.\u003c/p\u003e \u003cp\u003eThe results of this research collectively demonstrate significant advancements in a number of technological pillars, such as the development of multimodal biomedical sensing architectures, flexible antenna\u0026ndash;sensor co-design, high-resolution printing, and functional ink composition. Recent studies have reviewed flexible and wearable antenna materials, construction, and applications[\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e] .With these advancements, inkjet printing is now positioned as a key enabling technology for ongoing, individualized health monitoring. Nevertheless, despite these developments, a number of unresolved issues still prevent widespread clinical deployment, including mechanical durability under real-world motion, degradation from perspiration and moisture, limited wireless power availability, and the lack of standardized benchmarking or regulatory testing protocols. The important gaps and limits covered in the next part are directly motivated by these enduring constraints.\u003c/p\u003e"},{"header":"6. Critical Gaps and Limitations","content":"\u003cp\u003eSignificant obstacles still exist in the areas of materials, device physics, system integration, and translational preparedness, even in the face of notable advancements in inkjet-printed electronics and wireless power transmission for biomedical monitoring. This review offers a thorough evaluation of these restrictions, emphasizing the shortcomings of the technologies in use today:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eMechanical fatigue and structural degradation\u003c/b\u003e: Reliability in actual wearable and implantable situations is hampered by the frequent breaking, delamination, resistance drift, or loss of functionality of printed conductive traces and sensing layers during cyclic bending, stretching, perspiration exposure, and prolonged skin adhesion. Reliability is the likelihood that a bioelectronic device will perform as intended over a specific period and under expected operational conditions[\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eParasitic losses and limited harvested power\u003c/b\u003e: Coil misalignment, electromagnetic detuning, impedance mismatch, and environmental parasites all significantly lower the efficiency of wireless power transfer. For high-bandwidth biomedical applications or multi-sensor applications, RF energy harvesting usually produces power that is insufficient (in the \u0026micro;W\u0026ndash;mW range). Energy harvesting, often called energy scavenging, converts environmental energy into electricity [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eBiosafety and long-term biocompatibility concerns\u003c/b\u003e: Long-term interaction with carbon nanomaterials, printed polymers, and metallic nanoparticles (like AgNP) can cause skin irritation or cytotoxicity. Additional issues with chronic implantation include inflammation, ink residue leaking, and destruction by body fluids. Silver nanoparticles (AgNPs) are popular for their antibacterial and biological characteristics[\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eClinical under-validation and limited human studies\u003c/b\u003e: Most published systems are only shown in small volunteer studies, brief pilot tests, or benchtop environments. Medical adoption is restricted by the lack of strong clinical trials, long-term evaluations, and regulatory-grade validation.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eSignal fidelity and susceptibility to noise\u003c/b\u003e: Motion artifacts, impedance instability, temperature drift, and electromagnetic interference are all problems that printed sensor systems face.Based on electrical and mechanical properties, it investigates various materials for sensor electrode and substrate development [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. Accurate biochemical or electrophysiological signal capture is made more difficult by the numerous noise channels introduced by wireless powering.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eLack of standardized testing protocols\u003c/b\u003e: For the evaluation of printed WPT-powered biomedical devices, there is no standard framework. Rectenna and power transmission efficiency affect WPT system efficiency[\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e]. Cross-study comparison is challenging as translational progress is slowed by variations in ink compositions, printing parameters, power transfer configurations, and biosensing metrics.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eBy methodically recognizing these obstacles, this analysis makes it clear where innovation is most urgently needed and lays the groundwork for future research to focus on batteryless biomedical systems that are clinically viable, dependable, and scalable.\u003c/p\u003e"},{"header":"7. Future Research Directions","content":"\u003cp\u003eThis paper presents a forward-looking path for the creation of next-generation inkjet-printed, wirelessly powered biomedical systems, building on technology advancements and acknowledged constraints. A number of important study paths become apparent:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eHybrid multi-method printing strategies\u003c/b\u003e: Inkjet printing will be used more often in future devices in conjunction with screen printing, gravure, aerosol jet, extrusion-based, or laser sintering processes. High-performance, multi-material, three-dimensional device architectures that are suited to biomedical requirements can be made possible by this hybrid technique, which can overcome present constraints in resolution, conductivity, multilayer alignment, and stretchability.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eBiodegradable, biocompatible, and self-healing printed electronics\u003c/b\u003e: Transient biomedical implants will be made possible by sustainable printed electronics based on biodegradable substrates (cellulose, silk fibroin, polylactic acid) and environmentally friendly conductive inks. In the meantime, dynamic covalent networks and self-healing polymers offer improved mechanical reliability under cyclic deformation, enhancing durability during actual wear.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eUltra-low-power IC and circuit co-integration\u003c/b\u003e: Future systems must incorporate ultralow-power ASICs, energy-efficient analog front-ends, and adaptive power management circuits to get around WPT's energy constraints, particularly with regard to RF harvesting. Multi-sensor operation on microwatt-level power budgets will require advancements in passive amplification, near-threshold CMOS computation, and rectifier efficiency optimization.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eAI-assisted sensing, analytics, and digital health pipelines\u003c/b\u003e: Personalized health interventions, motion artifact correction, physiological trend prediction, and signal fidelity enhancement are all made possible by machine learning and artificial intelligence algorithms. Inkjet-printed sensors will become sophisticated, predictive healthcare solutions when AI is integrated at the edge (on-device inference) or through secure cloud pipelines.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003e \u003cb\u003eClinical translation, standardization, and regulatory frameworks\u003c/b\u003e: In order to go from lab prototypes to clinically deployable devices, future research must give priority to longitudinal studies, human subject trials, and medical-grade benchmarks. Regulatory approval and commercial acceptance will be accelerated by standardizing printing parameters, biosensing metrics, wireless power transfer efficiency, safety limitations, and biocompatibility testing.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eTogether, these research avenues pave the way for inkjet-printed biomedical systems that are clinically relevant, scalable, and battery-free. The field is positioned to provide revolutionary solutions for continuous and individualized healthcare monitoring by developing power electronics, fabrication engineering, materials science, and clinical validation.\u003c/p\u003e"},{"header":"8. Novelty and Contributions","content":"\u003cp\u003eFor the first time, this systematic analysis offers a cohesive, ten-year synthesis of the relationship between wireless power transmission and inkjet-printed electronics, particularly for biomedical monitoring applications. Although printed electronics, wearable sensors, and wireless powering have all been explored separately in earlier reviews, none of them have thoroughly combined these fields within a biological setting. The current work makes a number of original contributions:\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003e1. Multi-Domain Integration\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThis review methodically synthesizes developments in the following areas to bring together previously disparate research streams:\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eInkjet printing materials\u003c/strong\u003e, such as carbon-based nanomaterials, conductive polymers, and metallic nanoparticles;\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eFunctional inks and substrates\u003c/strong\u003e, covering materials that are biocompatible, stretchy, and flexible;\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eBiochemical and biophysical sensing mechanisms\u003c/strong\u003e, encompassing mechanical, thermal, electrochemical, and electrophysiological modes;\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eWireless power transfer mechanisms\u003c/strong\u003e, including advancements in RF energy harvesting, NFC, and inductive coupling designed for ultra-low-power devices;\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eWearable and implantable biomedical systems\u003c/strong\u003e, showcasing device designs that combine WPT with printed sensors for ongoing, battery-free monitoring.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eUnderstanding how fabrication technologies, power delivery methods, and biomedical needs come together to provide next-generation health monitoring platforms requires an integrated viewpoint.\u003c/p\u003e"},{"header":"9. Conclusion","content":"\u003cp\u003eA significant technological advancement in the development of contemporary biomedical monitoring systems is represented by inkjet-printed sensors that are powered by wireless energy transmission. Nowadays, wireless power transfer (WPT) technologies are common[\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e].They are positioned as top contenders for next-generation wearable, epidermal, and implantable health technologies due to their intrinsic benefits, which include lightweight structure, mechanical flexibility, low-cost fabrication, digital manufacturability, and the elimination of cumbersome on-board batteries. All of the fundamental pillars of this field\u0026mdash;functional ink engineering, substrate optimization, high-resolution additive manufacturing, printed antenna and coil design, and multimodal biomedical sensor integration\u0026mdash;have seen significant advancements over the last ten years.\u003c/p\u003e \u003cp\u003eInkjet printing combined with wireless power transfer modalities including NFC, inductive coupling, and RF energy harvesting has enabled a new generation of batteryless platforms for continuous, event-driven, or on-demand physiological monitoring. These integrated devices show promise in biochemical sweat sensing, electrophysiology, wound health evaluation, hydration tracking, temperature mapping, and minimally invasive implanted diagnostics. Ultrathin, conformal, and discreet form factors improve translational potential, therapeutic relevance, and user comfort.\u003c/p\u003e \u003cp\u003eIn spite of these advances, numerous basic difficulties persist. Long-term deployment is limited by mechanical durability under load, sweat, and constant motion. In RF-harvested systems, wireless power limits operational budgets, sampling rates, and multi-sensor integration. Long-term biosafety concerns with encapsulating materials, polymer additives, and metallic nanoparticle inks require more research. Motion, temperature, and skin\u0026ndash;sensor interface changes can impair signal quality. Lack of human-subject studies, clinical workflow integration, and standardized benchmarking remain barriers to regulatory approval and practical implementation.\u003c/p\u003e \u003cp\u003eHowever, emergent innovation avenues provide hope. For complicated, layered designs, hybrid multi-method additive production provides precision and conductivity. Self-healing, biodegradable, and eco-friendly printed materials can extend gadget life and biocompatibility. Ultra-low-power circuit topologies maximize RF-harvested platform viability. AI-enhanced biosignal analytics reduce noise, extract biomarkers, and provide personalized health insights. Multi-modal wireless powering strategies\u0026mdash;combining solar microharvesting, inductive, RF, and\u003c/p\u003e \u003cp\u003eNFC\u0026mdash;may improve operational robustness in varied situations.\u003c/p\u003e \u003cp\u003eThis systematic study describes how inkjet-printed, wirelessly powered biomedical sensors go from lab prototypes to clinically validated, scalable, and widely adopted healthcare devices. This vision requires coordinated advances in materials science, flexible electronics, wireless power engineering, device packaging, biosignal processing, regulatory science, and human-centered clinical research.\u003c/p\u003e \u003cp\u003eEngineering advances, supportive clinical guidelines, regulatory frameworks, and commercialization channels that ensure safe, cheap, and equitable deployment will be needed to integrate these technologies into real-world healthcare. Through interdisciplinary collaboration, inkjet-printed, battery-free biomedical gadgets could revolutionize customized digital health, chronic disease management, and preventative medicine worldwide.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch3\u003e\u003cstrong\u003eAcknowledgment\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThe authors thank the Department of Computer Science and Engineering at Islamic University, Kushtia, Bangladesh, for its academic and institutional support throughout the development of this study, \u0026ldquo;Inkjet-Printed Sensors Powered by Wireless Power Transfer for Biomedical Monitoring: A Decade of Evidence \u0026mdash; A Systematic Review.\u0026rdquo; The University of Alabama at Birmingham, Trine University, and Western Illinois University provided scholarly resources, technical support, and a collaborative academic atmosphere that helped the writers complete this work.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eFunding Declaration\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eNo public, commercial, or non-profit grants supported this research.\u003c/p\u003e\n\u003ch3\u003e\u003cstrong\u003eConflict of Interest\u003c/strong\u003e\u003c/h3\u003e\n\u003cp\u003eThe authors declare no financial or personal affiliations that could have influenced this manuscript\u0026apos;s findings.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eG. 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Taniar, Eds., Singapore: Springer Nature, 2025, pp. 301\u0026ndash;312. doi: 10.1007/978-981-97-8336-6_23.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Inkjet printing, printed electronics, wireless power transfer, NFC powering, flexible biosensors, wearable biomedical sensors, batteryless physiological monitoring","lastPublishedDoi":"10.21203/rs.3.rs-8464801/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8464801/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eOver the past ten years, inkjet-printed electronics have advanced quickly, making it possible to create flexible, biocompatible, and reasonably priced biomedical sensors that are appropriate for ongoing, covert physiological monitoring. Simultaneously, batteryless, ultra-thin, and very compliant biomedical systems have been made possible by wireless power transfer (WPT) technologies, such as inductive coupling, near-field communication (NFC), and radio-frequency (RF) energy harvesting. For next-generation wearable and implantable platforms that need mechanical softness, long-term stability, and continuous operation without heavy, inflexible batteries, the convergence of these two domains is very important.\u003c/p\u003e \u003cp\u003eTen years' worth of research on inkjet-printed sensors with wireless charging systems for biomedical monitoring is compiled in this systematic review (2015\u0026ndash;2025). We created a structured Google Scholar search strategy utilizing Boolean operators, categorized keyword sets, predetermined inclusion and exclusion criteria, and methodical screening processes in accordance with PRISMA 2020 principles. In order to enable a variety of biomedical applications, such as biochemical sweat sensing, electrophysiology, wound monitoring, hydration detection, thermal mapping, and multimodal physiological surveillance, the analysis highlights significant developments in printable materials, fabrication techniques, sensing architectures, and WPT modalities.\u003c/p\u003e \u003cp\u003eSignificant obstacles still exist in the sector despite evident advancements, including restricted wireless power supply, mechanical deterioration under stress, ink instability, substrate\u0026ndash;ink mismatch, biosafety concerns, and a lack of clinical validation or standardized testing. Hybrid additive manufacturing, sustainable and biodegradable printed materials, self-healing conductors, ultra-low-power electronics, multiparametric sensing arrays, and AI-driven signal interpretation are examples of emerging potential. All things considered, this analysis highlights the revolutionary potential of entirely batteryless, wirelessly powered, inkjet-printed biomedical systems and offers a thorough road map for bringing them closer to clinical-grade dependability and broad acceptance.\u003c/p\u003e","manuscriptTitle":"Inkjet-Printed Sensors Powered by Wireless Power Transfer for Biomedical Monitoring: A Decade of Evidence — A Systematic Review","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-06 13:53:04","doi":"10.21203/rs.3.rs-8464801/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e4b45390-89f9-4036-8203-9725d8574cd0","owner":[],"postedDate":"January 6th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":60287000,"name":"Biomedical Engineering"}],"tags":[],"updatedAt":"2026-01-06T13:53:04+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-06 13:53:04","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8464801","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8464801","identity":"rs-8464801","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}