Preserving exposed hydrophilic bumps on multi-bioinspired slippery surface arrays unlocks high-efficiency fog collection and cleaning

Preserving exposed hydrophilic bumps on multi-bioinspired slippery surface arrays unlocks high-efficiency fog collection and cleaning | 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 Article Preserving exposed hydrophilic bumps on multi-bioinspired slippery surface arrays unlocks high-efficiency fog collection and cleaning Yan Yan, Junda Wu, Chunxiang Li, Jiangdong Dai This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5840260/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 06 Nov, 2025 Read the published version in Nature Communications → Version 1 posted You are reading this latest preprint version Abstract The efficiency of fog water collection technologies is inherently hindered by the long-standing dilemma of nucleation vs. transportation balance. Inspired by nature, we address this issue by preserving hydrophilic bumps on slippery liquid-infused porous surfaces (SLIPS) through an underwater infusion strategy, creating a super-slippery fog collector with multi-scale biomimetic structures. This surface combines features from beetle carapaces and pitcher plant surfaces, enabling rapid initial nucleation on hydrophilic bumps and efficient droplet transport. As a result, we have developed the most efficient fog collecting surface reported to date, capturing 5000–60000 mg/cm² per hour with fog flow rates ranging from 300–1500 mL/h. By macroscopically scaling and optimizing, we have constructed an integrated 3D fog collecting device capable of capturing over 660 g of water in 500 minutes. Further integrating TiO 2 into the bumps imparts the ability for simultaneous water collection and purification without sacrificing collection efficiency. Our work reveals that resolving the nucleation-transport dichotomy is key to achieving high-efficiency fog water collection. Earth and environmental sciences/Environmental sciences/Environmental chemistry Physical sciences/Chemistry/Energy Physical sciences/Energy science and technology/Energy harvesting/Devices for energy harvesting Physical sciences/Chemistry/Green chemistry/Sustainability Physical sciences/Chemistry/Surface chemistry Figures Figure 1 Figure 2 Figure 3 Figure 4 Introduction Water scarcity remains one of the most critical challenges facing the global population, particularly in arid and semi-arid regions where conventional water sources are often limited 1 – 3 . In these areas, atmospheric water in the form of fog represents an underexploited resource that could significantly alleviate water shortages if effectively collected 4 . The primary challenge of current fog harvesting systems lies in optimizing the nucleation vs. transportation balance of water droplets; these two processes are crucial for efficient water collection but are inherently contradictory in principle 5 , 6 . On conventional large mesh nets made of woven polymer 7 , 8 , typically only one of these aspects can be optimized by adjusting the wettability, leaving it an unresolved dilemma. Inspired by nature’s unique structures and properties, innovative advancements in material surface and interface technologies have been made to enhance the water collection rate 9 – 12 . One such innovation mimics the carapace of desert beetles 13 , where an interlaced configuration of hydrophilic microstructures can easily capture tiny fog droplets until they grow large enough to roll off. This surface Janus structure undoubtedly accelerates the initial nucleation of water droplets. However, its alternating hydrophilic and hydrophobic surface distribution creates adhesion that hinders droplet detachment and surface migration 14 , 15 . Consequently, desert beetles need to tilt its body towards to the wind flow and the water droplets with the diameter of critical size could be transported to their mouths. Interestingly, nature also provides solutions to the problem of droplet transportation, pointing towards the construction of slippery liquid-infused porous surfaces (SLIPS) 16 , inspired by the water-slippery nature of peristome from the Nepenthes pitcher plant to hunt insects 17 . With only a certain angle of inclination, little droplets can be easily slid, transported, and collected by SLIPS. However, constructing stable SLIPS necessitates a superhydrophobic substrate infused with inert hydrophobic lubricating oil 16 , which creates a significant water nucleation barrier, thus constraining the whole water collection rate. Given the limitations of these single bio-inspired structures in addressing either nucleation or transport, the key steps in fog harvesting, we propose that combining the characteristics of both structures could be an optimal solution. By constructing superhydrophobic SLIPS with exposed hydrophilic bumps on top, we can ideally balance the nucleation and transportation of water droplets (Scheme 1a ). However, a significant challenge is that, according to surface energy theories 18 , hydrophilic components are also inherently oleophilic in air. This means that during traditional lubricating oil infusion processes, the hydrophilic bumps are bound to be wrapped by oil. Thus, although much desired, achieving a stable superhydrophobic SLIPS with exposed hydrophilic top structures is extremely challenging. In this work, we developed an underwater lubricating oil infusion strategy for multi-bio-inspired SLIPS, preserving exposed hydrophilic bumps on the hydrophobic lubricating substrate (as illustrated in Scheme 1b ). This design facilitates rapid initial nucleation at hydrophilic bumps, combined with the efficient sliding transport of the formed water droplets, effectively solving the longstanding dilemma between nucleation and droplet transport. Results Sample fabrication and characteristic analysis Inspired by the hydrophilic/hydrophobic hybrid microstructure on desert beetle back carapace, we designed a Janus structure of hydrophobic Cu(OH) 2 nanorods topped with hydrophilic BaSO 4 nanoparticles (Scheme 1a ) via top interfacial growing (TIG) process (details of the preparation method see Supplementary Figure S1 a ). The as-prepared Janus substrate was denoted as Cu-SHBL. Additionally, drawing inspiration from the water-slippery nature of the Nepenthes pitcher plant, we constructed SLIPS on the Cu-SHBL substrate via underwater lubricating oil infusion, which could preserve the exposed hydrophilic BaSO 4 bumps (Scheme 1b , details of the preparation method see Supplementary Figure S1 b ). For comparison, oil infusion was also conducted in air on the same substrate and served as a reference. Due to the superhydrophobic property of embedded fluorinated Cu(OH) 2 nanorods and the presence of hydrophilic BaSO 4 nanoparticles on top, a strong wetting gradient was formed. Therefore, during underwater oil infusion, water effectively encapsulated the hydrophilic BaSO 4 nanoparticles, allowing the lubricating oil to compactly and uniformly coat the substrate without contaminating the hydrophilic bumps and completely displacing air within the gaps of superhydrophobic nanorods, forming the Cu-SHBL-SLP film (Scheme 1b ). In contrast, oil-infusion in air not only contaminated the hydrophilic BaSO 4 nanoparticles but also left air gaps within the film. This was reflected as the change in the amount of infused lubricating oil, where underwater infused Cu-SHBL film has 22% higher oil infusion amount compared to the air-infused counterpart (Fig. 1 a), indicating that underwater infusion strategy is more effective in excluding air within the film and more conducive to even distribution of the lubricant ( Supplementary Figure S2 ). As a protective measure during the oil infusion process, the hydrophilic BaSO 4 bumps on top of the Cu-SHBL films were largely preserved and remained exposed, as observed in the different fog capture processes using Environmental Scanning Electron Microscopy (ESEM), shown in Supplementary Figure S3 ( details of the process see Supplementary Movie S1 and 2) . Furthermore, the Cu-SHBL film infused underwater exhibited a smaller water contact angle but a larger water sliding angle compared to its air-infused counterpart (Figs. 1 b and 1 c), further confirmed the exposure of the on-top hydrophilic BaSO 4 nanoparticles. Typically, the loss of lubricating oil is the major limitation for long-term continuous applications of SLIPS 19 . Our underwater-infused SLIPS retained about 45.7% more lubricant than its air-infused counterpart after undergoing a spin process at 1500 rpm for 60 s (Fig. 1 d), which also demonstrated commendable stability during long-term fog collecting applications for over 20 runs (Fig. 1 e). The underwater-infused Cu-SHBL-SLP with exposed hydrophilic bumps demonstrated 33.2% higher water collection rate (WCR) compared to its air-infused counterpart under the same experimental condition. This design featured exposed hydrophilic bumps on the hydrophobic SLIPS, which allowed the droplets to grow quickly and facilitates their removal. As illustrated in Figs. 1 f and 1 g, the underwater-infused Cu-SHBL-SLP showed a significantly larger critical droplet removal size of ~ 1.116 mm, in contrast to the ~ 0.642 mm observed with the air-infused version. Although the time to remove individual droplets had increased, this led to the accumulation of larger droplets over the same period, enhanced overall water collection rate. Surface wettability and water adhesion control Furthermore, we compared the WCR of various film stages—Cu, Cu-SHL, Cu-SHB, Cu-SHBL, and Cu-SHBL-SLP (details of the various of films see Supplementary Figure S6-S17 ) —to confirm the effectiveness of our design, which incorporated exposed hydrophilic bumps on SLIPS for collecting fog (Fig. 2 a). Generally, the optimal scenario for fog-collection was featured by a shorter time and a heavier weight for the first droplet removal (FDR). We used a high-speed camera to measure the FDR time and weight across different films (Fig. 2 b). Results showed that on the hydrophilic surfaces of Cu and Cu-SHL, although the FDR weight was very large (> 0.3g), the FDR time was significantly long (> 350 s) due to strong water adhesion. Following the hydrophobic treatment reduced surface adhesion to water, the Cu-SHB and Cu-SHBL films exhibited significantly shorter FDR times. However, the absence of water aggregation centers on superhydrophobic surface resulted in small first droplets, with the FDR weight less than 10 − 4 g (These tiny droplets, too small to weigh, were estimated using magnified images during the water collection process, as detailed in the Supplementary Figure S15 and S16 ). The introduction of underwater oil infusion on the Cu-SHBL-SLP film resulted in both a shorter FDR time and an FDR weight greater than 0.01g. This confirmed that the hydrophilic bumps on SLIPS acted as effective central sites for tiny water droplets capturing and coalescing. Detailed observations of the corresponding water collection process were available in the Supplementary Figure S13-S17 . By adjusting the amount of BaSO 4 hydrophilic bumps on Cu-SHBL-SLP (details of the samples morphology see Supplementary Figure S18 ), we identified the optimal hydrophilic bump loading at a Ba content of 0.53 wt % (Fig. 2 c). Notably, before oil infusion, an increase in the number of BaSO 4 hydrophilic bumps led to greater adhesion of the Cu-SHBL to water droplets, which consequently increased the rolling angle of individual droplets ( Supplementary Figure S19 and S20 ). This trend of enhanced water adhesion not only persisted but intensified after underwater oil infusion, confirming that the our strategy effectively preserved the exposed hydrophilic bumps (Fig. 2 d and 2 e). Note that an excessive number of hydrophilic BaSO 4 bumps can even hinder the surface transport of water droplets, leading to a reduced WCR (Fig. 2 c). Using a high-speed camera, we observed the average droplet removal size on Cu-SHBL-SLP surfaces (positioned at 90 degrees) with varying numbers of BaSO 4 hydrophilic bumps and calculated corresponding water adhesion constants ( Supplementary Figure S21-24 ). Result showed that the adhesion constant of droplets to the film surface increases exponentially with the number of hydrophilic bumps, supporting our conclusions (Fig. 2 f, Supplementary Figure S23 and Figure S24 ). A comparison of Cu-SHBL-SLP films with different contents of hydrophilic bumps revealed that the sample with a 0.53 wt % Ba content offers the optimal balance, resulting in the optimal FDR time and weight (Fig. 2 g). Initial capture and nucleation of water droplets from microscopic views Exposed hydrophilic bumps enhanced adhesion to water molecules, which accelerated the capture and coalescence of water droplets. To substantiate this observation at the microscopic level, we monitored the dissociation of water molecules adsorbed on Cu-SHBL-SLP surfaces with varying hydrophilic bump contents (Ba content of 0 ~ 1.54 wt %) using in situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS). Under continuous water vapor flow, the DRIFTS spectra from different Cu-SHBL-SLP surfaces showed three types of infrared absorption bands located at 3447 cm − 1 , 3250 cm − 1 , and 1644 cm − 1 . These bands correspond to the dissociated water’s O-H stretching vibrations, water molecules’ O-H stretching vibrations, and H-O-H bending vibration, respectively (Fig. 3 a). The results demonstrated that as the number of hydrophilic bumps increased, the efficiency of water molecule dissociation significantly improved (Figs. 3 b, 3 c). This revealed that BaSO 4 hydrophilic bumps on SLIPS promoted the chemical dissociation equilibrium of water molecules, thereby increased water affinity and accelerated the formation of initial droplets and subsequent aggregation of fog droplets (Figs. 3 d, 3 e). An identical droplet formation process was also computationally simulated via molecular dynamics (MD) simulations. As shown in Fig. 3 f, on SLIPS without hydrophilic bumps, water vapor, lacking aggregation centers, aggregated slowly and randomly in the groove on the substrate, formed the initial droplets over a 500 ps timescale. In contrast, as shown in Fig. 3 g, the presence of exposed hydrophilic BaSO 4 bumps on SLIPS naturally served as centers of water molecule affinity. This allowed initial droplets to form and stabilize within 20–30 ps, accelerated the process by more than a tenfold. From 2D patterns to 3D arrays Leveraging the characteristic of exposed hydrophilic bumps on SLIPS, we had further developed reverse Christmas tree-shaped Cu-SHBL-SLP patterns, inspired by desert cacti (Fig. 4 a). Through laser ablation, we precisely adjusted the length (L) and inclination angle (θ) of the serrated edges of the pattern templates ( Supplementary Figure S25 and S26) . This adjustment imparted unique Laplace pressures to the 2D sheet that influence the coalescence and transportation of water droplets 20 (Figs. 4 d, Supplementary Movie S3 ). This distinctive patterned structure facilitated the coalescence and transportation of multiple droplets within ~ 72 s, which was four times faster than the pristine, unpatterned Cu-SHBL-SLP film (> 285 s). In this structure, the length L should not be overly long. An appropriate L provided sufficient Laplace pressure to aid water movement, but an excessively high L increased the transportation distance of the droplets from the tip to the base, thereby added unnecessary time for droplet coalescence in the central channel (Fig. 4 b). The inclination angle θ was also important; generally, the smaller the θ, the greater the combined effect of gravity and Laplace forces, enhanced the efficiency of droplet coalescence and transportation. When θ exceeded 90 degrees, gravity counteracted the Laplace pressure. However, within a range of θ = 30 ~ 60 degrees, an increase in θ benefited the initial fog capture process, making θ = 60 degrees the optimal parameter for WCR (Fig. 4 c). This optimization is based on the observation that a smaller inclination angle impeded the initial fog capture along the span direction, negatively affected the WCR ( Supplementary Figure S27 and Movie S4 ). Under the conditions of L = 1 cm and θ = 60 degrees, the patterned Cu-SHBL-SLP achieved the WCR over 5000 mg/cm² h at 300 mL/h and reached up to 60000 mg/cm² h at 1500 mL/h, marked the highest water collection performance reported to date with fog flow outputs ranging from 420 to 1500 mL/h (Fig. 4 e). Note that water collection performance was largely depended on the water content in the ambient fog environment. Our analysis only compared the top 20 representative fog collection systems with clearly specified fog flow conditions and no external energy input (Fig. 4 e and Supplementary Table S2 ), and our system surpassed all previously reported systems when the output fog flow exceeded 420 mL/h. Furthermore, inspired by the fog collection enhancement effect observed in densely arrayed plants in the forest 21 , we constructed an integrated fog collection device by assembling 2D patterned sheet into densely arranged 3D arrays to maximize the extraction of moisture from the air (Fig. 4 f). The sealed box beneath the arrays served as storage to minimize loss from volatilization. The fog collection device consistently collected more than 660 g of water within 500 min (Fig. 4 g and Fig. 4 h). Moreover, considering the dual challenges of water scarcity and pollution, integrating water collection with purification processes addresses two critical environmental issues simultaneously. This approach is particularly vital in regions affected by both limited water resources and high levels of atmospheric pollutants, such as the volatile organic compounds (VOCs), environmental pesticide residues, and other organic pollutants, can lead to the contamination of collected water, rendering the limitation of direct use 22 , 23 . Traditional methods of water purification often require extensive infrastructure and significant energy inputs, which are not always feasible in remote or economically disadvantaged areas. By developing systems that can both collect and purify fog, we can harness naturally occurring water sources and ensure that the water is safe for consumption and other uses immediately upon collection 24 . Leveraging the unique structure of hydrophilic bumps on SLIPS, hydrophilic photocatalysts, i.e., TiO 2 nanoparticles, widely used in photocatalytic water pollution remediation 25 , can easily adhere to the hydrophilic bumps due to similar wettability, thereby endowing these exposed tips with photocatalytic water purification capabilities (Fig. 4 i and 4 j). By placing as-prepared Cu-SHBL(Ti)-SLP film under UV light illumination, tiny fog droplets are purified by a significant amount of reactive oxygen species (ROS) generated during the initial capture and nucleation process by the TiO 2 nanoparticles. These tiny initial droplets also act as microreactors with a high gas-liquid exchange capacity and enhanced local ROS concentration, thus, their purification effect is usually more efficient than in bulk water 26 . We investigated the photocatalytic purification capacity of the TiO 2 -topped SLIPS sheet by adding the representative organic dye (Rhodamine B) pollution to the fog sources to simulate the photodegradation of organic pollutants during collection under UV irradiation, and the results showed that the dye molecules in the collected water were completely degraded without any residue (verified by both the photo images and UV-vis spectrophotometer). More importantly, during this process, the water collection performance of the SLIPS films was not compromised ( Supplementary Figure S28 ), confirming the high efficiency of this design in both water collection and purification. Discussion This work of ours, from the microscopic to the macroscopic, developed a comprehensive solution to water sustainability by combining multiple bioinspired designs (desert beetle back, pitcher plant slippery surface, cactus patterned structure and densely arrayed plants) with advanced material science. By maintaining the structure of hydrophilic bumps on SLIPS and integrating TiO 2 photocatalysts, our system efficiently collects and purifies fog, gathering over 660 grams of water in 500 min. The key to this design is the successful preservation of the exposed hydrophilic bumps through underwater lubricant-oil infusion process, which resolves the longstanding dilemma of the nucleation vs. transportation balance in the field. This breakthrough ensures strong nucleation capabilities along with efficient transportation, thus achieving record-breaking water collection results under mid-to-high fog flow condition (420 ~ 1500 mL/h). The future perspective of this work aims to scale and refine this technology, enhancing its application potential through the development of portable, energy-efficient, and cost-effective products. Experimental section Chemicals Copper sheet (0.1 mm) was purchased from Biling factory. 1H,1H,2H,2H-Perfluorooctyltriethoxysilane (PFTS) was obtained from Bidepharm. Sodium hydroxide (NaOH), ammonium persulfate ((NH 4 ) 2 S 2 O 8 ), barium chloride (BaCl 2 ), potassium sulphate (K 2 SO 4 ), ethanol and acetone were purchased from Sinopharm Chemical Reagent Co., Ltd. Polyperfluoromethylisopropyl ether (PFPE) were gained from Aladdin Reagent Co. Deionized water (DI water) was applied in all the experimental processes. All the chemicals were applied without any other purification. Preparation of Cu-SHBL film The original copper sheet (20 mm × 20 mm) was first washed with detergent, acetone, ethanol and DI water respectively. Then the cleaned Cu sheet was immerged into the mixed solution containing 2.5 m NaOH and 0.13 m (NH 4 ) 2 S 2 O 8 for 15 min to obtain the Cu/Cu(OH) 2 , named as Cu-SHL. To endow the water-repellent ability, the Cu-SHL was immerged into the PFTS ethanol solution and dried at 50℃ in air, which was named as Cu-SHB. Then, the superhydrophobic nanorods with hydrophilic particles on its top was achieved via unique top interfacial growth (TIG) process. Firstly, the superhydrophobic Cu-SHB was clamped by two glass tubes with the diameter of 1.5 cm. Then 0.1 m BaCl 2 aqueous solution was poured into the glass tube above. The aqueous solution could not wet the beneath sheet and kept a Cassie state due to the low surface energy and high roughness of the fluorinated Cu(OH) 2 nanorod arrays. The superhydrophobic nanorods could prevent the sheet to be wetted while only the top of nanorods could contact to the aqueous solution, which provided a feasible strategy to realize the top modification. A dropper with 0.1 m K 2 SO 4 aqueous solution was forced into the above aqueous solution and ejected onto the top surface of Cu-SHB. Consequently, the BaSO 4 sediment could be formed on the nanorods, and regarded as the Cu-SHBL film. Underwater lubricating oil infusion process To construct the slippery liquid-infused porous surface (SLIPS), PFPE was selected as the lubricating oil and conducted the underwater oil infusion process. Firstly, the prepared Cu-SHBL film was placed into the bottom of Petri dish filled with DI water under the external forced. Then 500 µL PFPE was taken by a pipette gun and dropped onto the Cu-SHBL film surface, realized the underwater lubricating oil infusion process. After placed in water for 10 min, the sheet was vertically dried at room temperature overnight. And the obtained sheet was named as Cu-SHBL-SLP. To make a comparation, the Cu-SHB was as the substrate and conducted the underwater lubricating oil infusion process, which was named as Cu-SHB-SLP. Water harvesting measurement The water harvesting process of the prepared material was evaluated by the homemade testing system. The fog flow with 300–1500 mL/h was provided by the ultrasonic humidifier 27 (YADU ultrasonic humidifier YC − D205, China and AUX mechanical standards, Hefei Hemei E-commerce Co., Ltd.). The temperature and relative humidity (RH) were 20°C and 90%, respectively. All the studied meshes were clamped on a holder with a fixed distance of 6 cm to the humidifier nozzle, and all the valid collection areas of the meshes were 3.14 cm 2 for 2D sheet and different valid area for 3D patterned sheet. Without any further illustration, the fog flow was normally perpendicular to the mesh surface. The collected water was stored using a self-made container, and the mass of the collected water was calculated every 10 min. The water collection mass (WCM) was calculated with the following equation: $$\:WCM=\frac{M}{A}$$ 1 where M (mg) is the amount of the collected water and A (cm 2 ) is the valid area of the meshes. The water collection rate (WCR) was calculated with the following equation: $$\:\text{W}\text{C}\text{R}=\frac{WCM}{t}=\frac{M}{A\times\:t}$$ 2 where t (h) is the experimental time of fog collection. Lubricating oil obtain/loss tests The lubricating oil obtain was determined by the weight of samples before and after the lubricating oil infusion process. The lubricating oil obtain could be calculated as follows: $$\:\text{L}\text{u}\text{b}\text{r}\text{i}\text{c}\text{a}\text{t}\text{i}\text{n}\text{g}\:\text{o}\text{i}\text{l}\:\text{o}\text{b}\text{t}\text{a}\text{i}\text{n}\:\left(\%\right)=\frac{{M}_{ob}-{M}_{oa}}{{M}_{ob}}$$ 3 where M ob (g) was the weight of the material before lubricating oil, M oa (g) was the weight of the material after lubricating oil. Due to the superoleophilic property of superhydrophobic Cu-SHB, the lubricating oil obtain test was conducted on two sides. The lubricating oil loss was determined by the weight of samples before and after the spin process or the fog collection test. The lubricating oil loss could be calculated as follows: $$\:\text{L}\text{u}\text{b}\text{r}\text{i}\text{c}\text{a}\text{t}\text{i}\text{n}\text{g}\:\text{o}\text{i}\text{l}\:\text{l}\text{o}\text{s}\text{s}\:\left(\%\right)=\frac{{M}_{lb}-{M}_{la}}{{M}_{lb}}$$ 4 where M lb (g) was the weight of the material before tests, M la (g) was the weight of the material after tests. MD simulations In this work, the classical molecular dynamics simulation method 28 is used to study the water adsorption properties of SLIPS in two different microscopic structure, i.e., with hydrophilic BaSO 4 particles and without BaSO 4 components. The molecular structure of PFPE monomer unit and whole PFPE components are shown in the Supplementary Figure S29a and b . And the substrate contains 100 PFPE molecules as shown in Supplementary Figure S29c . 1000 water molecules were randomly placed above the substrate, as shown in Supplementary Figure S30a , and BaSO 4 nanoparticle is placed between the water and the substrate in one simulation system as shown in Supplementary Figure S30b . Both the initial configurations of solvent systems were constructed through the software of Material Studio, all the molecules were randomly inserted in a simulation box. The xy direction is set as periodic boundary conditions to characterize xy orientation as infinite in size. The molecular force field is consisted of nonbonded and bonded interaction. The nonbonded interaction contains van deer Waals (vdW) and electrostatic interaction, which is described by Eq. 5 and Eq. 6 , respectively. The function equations are as follows: $$\:{E}_{LJ}\left({r}_{ij}\right)=4{\epsilon\:}_{ij}\left({\left(\frac{{\epsilon\:}_{ij}}{{r}_{ij}}\right)}^{12}-{\left(\frac{{\epsilon\:}_{ij}}{{r}_{ij}}\right)}^{6}\right)$$ 5 $$\:{E}_{c}\left({r}_{ij}\right)=\frac{{q}_{i}{q}_{j}}{4\pi\:{\epsilon\:}_{o}{\epsilon\:}_{r}{r}_{ij}}$$ 6 For different kinds of atoms, the Lorentz-Berthelot mix rules were adopted for vdW interactions, which is following the Eq. 7 : $$\:{\sigma\:}_{ij}=\frac{1}{2}\left({\sigma\:}_{ii}+{\sigma\:}_{jj}\right);{\epsilon\:}_{ij}={\left({\epsilon\:}_{ii}*{\epsilon\:}_{jj}\right)}^{\frac{1}{2}}$$ 7 The cutoff distance of vdW and electronic interactions was set to 1.0 nm. For each simulation, an energy minimization was firstly employed to relax the simulation box. Then, a canonical (NVT) ensemble with the 1 fs time step is employed to optimized the simulation box, where the temperature is set as 273 K. The temperature is kept via the Nose-Hoover thermostat. The NVT optimization time was set to 1.0 ns, which is enough long to obtain a stable box size. During the relaxation process, restricting the adsorption of water molecules on the substrate. At last, another 0.5 ns NVT simulation was performed to adsorbed water molecules. In all the MD simulation, the motion of atoms was described by classical Newton’s equation, which was solved using the velocity-Verlet algorithm, and the simulation program is carried out by the large-scale simulation software LAMMPS 1 developed by the National Laboratory of the United States. Characterization devices The scanning electron microscopy (SEM, JSM-7800F, Hitachi, Japan) equipped with the energy-dispersive spectroscope (EDS) was used to study the surface morphology and structure. The environmental scanning electron microscope (ESEM, QUANTA200) was applied to study the water capture process of the prepared samples surface. The UV-visible spectrophotometer (Agilent Cary 8454) was used to test the organic pollution contents. The surface wettability was observed by the contact angle meter (LAUDA Scientific, China). The water droplet adhesive force of the sample surface was conducted via the Surface Tension Measuring Instrument (Kruss K100, German). Fourier transform infrared spectrometer (Nicolet Nexus 470, America), X-ray diffraction (XRD-6100, Japan) and X-ray photoelectron spectroscopy (XPS, Escalab 250Xi, America) were tested to analyze the chemical components and surface functional groups of the sample. In-situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) experiments were performed on a Thermo Nicolet iS10 spectrometer equipped with a mercury cadmium telluride (MCT) detector to study the dissociation of water molecules adsorbed on the prepared samples surface during fog collection process. Declarations Acknowledgments This work was financially supported by the National Natural Science Foundation of China (Nos. 22378173) and Graduate Research Innovation Program of Jiangsu Provincial (KYCX23_3648). References Trenberth KE et al (2013) Global warming and changes in drought. Nat Clim Change 4:17–22. 10.1038/nclimate2067 Mekonnen MM, Hoekstra AY (2016) Four billion people facing severe water scarcity. Sci Adv 2:e1500323. 10.1126/sciadv.1500323 Lord J et al (2021) Global potential for harvesting drinking water from air using solar energy. Nature 598:611–617. 10.1038/s41586-021-03900-w Klemm O et al (2012) Fog as a Fresh-Water Resource: Overview and Perspectives. Ambio 41:221–234. 10.1007/s13280-012-0247-8 Wang Y et al (2024) Improved Water Collection from Short-Term Fog on a Patterned Surface with Interconnected Microchannels. Environ Sci Technol 58:3812–3822. 10.1021/acs.est.3c09504 Lu H et al (2022) Materials Engineering for Atmospheric Water Harvesting: Progress and Perspectives. Adv Mater , e2110079. 10.1002/adma.202110079 Schemenauer RS, Cereceda PA (1994) Proposed Standard Fog Collector for Use in High-Elevation Regions. J Appl Meteorol Climatology 33:1313–1322. https://doi.org/10.1175/1520-0450(1994)0332.0.CO;2 Fernandez DM et al (2018) Fog Water Collection Effectiveness: Mesh Intercomparisons. Aerosol Air Qual Res 18:270–283. 10.4209/aaqr.2017.01.0040 Zheng Y et al (2010) Directional water collection on wetted spider silk. Nature 463:640–643. 10.1038/nature08729 Ju J et al (2012) A multi-structural and multi-functional integrated fog collection system in cactus. Nat Commun 3:1247. 10.1038/ncomms2253 Chen H et al (2018) Ultrafast water harvesting and transport in hierarchical microchannels. Nat Mater 17:935–942. 10.1038/s41563-018-0171-9 Park KC et al (2016) Condensation on slippery asymmetric bumps. Nature 531:78–82. 10.1038/nature16956 Parker AR, Lawrence CR (2001) Water capture by a desert beetle. Nature 414:33–34. 10.1038/35102108 Ji Y et al (2024) Nanoscale Drag Reduction Effect Enables Efficient Fog Harvesting. Adv Funct Mater. 10.1002/adfm.202411083 Wang Y et al (2022) Sustainable Superhydrophobic Surface with Tunable Nanoscale Hydrophilicity for Water Harvesting Applications. Angew Chem Int Ed 61. 10.1002/anie.202115238 Wong TS et al (2011) Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity. Nature 477:443–447. 10.1038/nature10447 Chen H et al (2016) Continuous directional water transport on the peristome surface of Nepenthes alata. Nature 532:85–89. 10.1038/nature17189 Su B, Tian Y, Jiang L (2016) Bioinspired Interfaces with Superwettability: From Materials to Chemistry. J Am Chem Soc 138:1727–1748. 10.1021/jacs.5b12728 Feng R et al (2020) A Bioinspired Slippery Surface with Stable Lubricant Impregnation for Efficient Water Harvesting. ACS Appl Mater Interfaces 12:12373–12381. 10.1021/acsami.0c00234 Chen Y et al (2020) Bioinspired Superwettable Microspine Chips with Directional Droplet Transportation for Biosensing. ACS Nano 14:4654–4661. 10.1021/acsnano.0c00324 Dawson TE (1998) Fog in the California redwood forest: ecosystem inputs and use by plants. Oecologia 117:476–485. 10.1007/s004420050683 Ghosh R et al (2023) Photocatalytically reactive surfaces for simultaneous water harvesting and treatment. Nat Sustain 6:1663–1672. 10.1038/s41893-023-01159-9 Ghosh R, Sahu RP, Ganguly R, Zhitomirsky I, Puri IK (2020) Photocatalytic activity of electrophoretically deposited TiO2 and ZnO nanoparticles on fog harvesting meshes. Ceram Int 46:3777–3785. 10.1016/j.ceramint.2019.10.100 Zhu H et al (2021) Integration of water collection and purification on cactus- and beetle-inspired eco-friendly superwettable materials. Water Res 206. 10.1016/j.watres.2021.117759 Sang L, Zhao Y, Burda C (2014) TiO2Nanoparticles as Functional Building Blocks. Chem Rev 114:9283–9318. 10.1021/cr400629p Ge Q et al (2023) Significant Acceleration of Photocatalytic CO2 Reduction at the Gas-Liquid Interface of Microdroplets**. Angew Chem Int Ed 62. 10.1002/anie.202304189 Di H, Wang Z, Hua D (2019) Precise size distribution measurement of aerosol particles and fog droplets in the open atmosphere. Opt Express 27:A890–A908. 10.1364/OE.27.00A890 Plimpton SJ (1993) Fast parallel algorithms for short-range molecular dynamics. J Comput Phys 117:1–19. 10.1006/JCPH.1995.1039 Schemes Scheme 1 is available in the Supplementary Files section Additional Declarations There is NO Competing Interest. Supplementary Files SupportingInformationVideo1.mp4 Supporting Information Video 1 SupportingInformationVideo2.mp4 Supporting Information Video 2 SupportingInformationVideo3.mp4 Supporting Information Video 3 SupportingInformationVideo4.mp4 Supporting Information Video 4 SupplementaryInformation.docx Supplementary Information Scheme1.png Scheme 1. The design of multi-bio-inspired SLIPS. (a) Illustration of combining the Janus structure inspired by the desert beetle’s back carapace with the SLIPS inspired by the Nepenthes pitcher plant for fog collection. (b) Substrate preparation and lubricating oil infusion steps for SLIPS with exposed hydrophilic bumps. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5840260","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":412646651,"identity":"74e03c0f-f1e7-4643-ad45-6cf1ce6eff14","order_by":0,"name":"Yan Yan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA30lEQVRIie3RMQrCMBSA4SdCdAhmkxShXuFJQR08TLOIY8ELFFw9gOIVHOINIoG6RLoWHCy4OmR0ELSOLm1Gwfxb4H3DewHw+X4xBR1rcUYJaKXsw42Q1iaZh6yVieN27Uja1OooWJlId4mD6OX7cUmxLWRmrAYKQ9ZX9SQo7hPkSIQ0Z6mTKYy2u7ieYGEqgVTIoiIbCjFeXEiMXMjrvdTV3RxIvh5zhRgFqQE3EhRkOUoxDhlkWB2ZN+/Sy/Xh9ny+Pl95s/YxG7JBAwG+wK9nw/gndiodpnw+n++vewNVB1JopdRIXgAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-2393-3017","institution":"Jiangsu University","correspondingAuthor":true,"prefix":"","firstName":"Yan","middleName":"","lastName":"Yan","suffix":""},{"id":412646652,"identity":"bea8f192-6989-40a9-918b-9a7952c9f214","order_by":1,"name":"Junda Wu","email":"","orcid":"","institution":"Jiangsu University","correspondingAuthor":false,"prefix":"","firstName":"Junda","middleName":"","lastName":"Wu","suffix":""},{"id":412646653,"identity":"78c7ba12-3517-4ecc-82b4-602ee75c82ce","order_by":2,"name":"Chunxiang Li","email":"","orcid":"","institution":"Jiangsu University","correspondingAuthor":false,"prefix":"","firstName":"Chunxiang","middleName":"","lastName":"Li","suffix":""},{"id":412646654,"identity":"44600b98-6b14-4f32-bc71-b9439465bc63","order_by":3,"name":"Jiangdong Dai","email":"","orcid":"","institution":"Jiangsu University","correspondingAuthor":false,"prefix":"","firstName":"Jiangdong","middleName":"","lastName":"Dai","suffix":""}],"badges":[],"createdAt":"2025-01-16 08:55:09","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5840260/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5840260/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41467-025-65169-1","type":"published","date":"2025-11-06T05:00:00+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":75888569,"identity":"2f877c22-d1d7-49bd-977f-3d88b41ee6ec","added_by":"auto","created_at":"2025-02-10 09:33:51","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1214791,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCharacterizations and fog collection performances on underwater-/air-infused Cu-SHBL-SLP.\u003c/strong\u003e \u003cstrong\u003e\u0026nbsp;(a)\u003c/strong\u003e The lubricating oil obtain mass, \u003cstrong\u003e(b)\u003c/strong\u003e water contact angle, \u003cstrong\u003e(c) \u003c/strong\u003ewater sliding angle, and \u003cstrong\u003e(d)\u003c/strong\u003elubricating oil loss mass after the spin process of 1500 rpm for 60 s on underwater-/air-infused Cu-SHBL-SLP; \u003cstrong\u003e(e)\u003c/strong\u003e the long-term fog collection performances and stabilities of underwater-/air-infused Cu-SHBL-SLP. (fog flow at 300 mL/h and every 30 min recorded as one cycle). Online optical observations of the water collection process on \u003cstrong\u003e(f)\u003c/strong\u003e air-infused and\u003cstrong\u003e(g)\u003c/strong\u003e underwater-infused Cu-SHBL-SLP (fog flow at 100 mL/h).\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/51b8e7606d1852eed1357db7.png"},{"id":75890198,"identity":"6f97ebed-1bc6-480b-8526-9a1756c6ee1c","added_by":"auto","created_at":"2025-02-10 09:41:51","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":646183,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSurface wettability and water adhesion control over various-stage films.\u003c/strong\u003e \u003cstrong\u003e(a)\u003c/strong\u003e Water collection rate (WCR) (fog flow at 300 mL/h) and \u003cstrong\u003e(b)\u003c/strong\u003e the comparison of first droplet removal (FDR) time and weight (fog flow at 100 mL/h) of the original Cu, Cu-SHB, Cu-SHL, Cu-SHBL-0.53% and Cu-SHBL-0.53%-SLP films; \u003cstrong\u003e(c)\u003c/strong\u003e comparisons of WCR (fog flow at 300 mL/h), \u003cstrong\u003e(d)\u003c/strong\u003e water contact angle, \u003cstrong\u003e(e)\u003c/strong\u003e water sliding angle, \u003cstrong\u003e(f)\u003c/strong\u003ecalculated droplet adhesion force, \u003cstrong\u003e(g)\u003c/strong\u003e FDR time and weight (fog flow at 100 mL/h) of various Cu-SHBL-SLP with different Ba content (Ba content was quantified by using EDS analysis as seen in \u003cstrong\u003eSupplementary Table S1\u003c/strong\u003e).\u003c/p\u003e","description":"","filename":"image2.png","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/df34ace499d72e84424c2aa7.png"},{"id":75887997,"identity":"804df1b1-77c1-4201-bc6c-db81ac02b321","added_by":"auto","created_at":"2025-02-10 09:25:50","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":660561,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eWater dissociation and capture mechanism on SLIPS with/without on-top hydrophilic bumps.\u003c/strong\u003e\u003cem\u003e \u003c/em\u003e\u0026nbsp;\u003cstrong\u003e(a)\u003c/strong\u003e \u003cem\u003eIn situ\u003c/em\u003e DRIFTS spectra collected from the continuous H\u003csub\u003e2\u003c/sub\u003eO adsorption on various Cu-SHBL-SLP films surfaces with different Ba contents; \u003cstrong\u003e(b) \u003c/strong\u003epeak ratio of 3250 cm\u003csup\u003e-1\u003c/sup\u003e to 3447 cm\u003csup\u003e-1\u003c/sup\u003e and \u003cstrong\u003e(c)\u003c/strong\u003e 1644 cm\u003csup\u003e-1\u003c/sup\u003e to 3447 cm\u003csup\u003e-1\u003c/sup\u003e of various Cu-SHBL-SLP films; \u003cstrong\u003e(d-e)\u003c/strong\u003e illustrations show surface dissociation state of water when the SLIPS with/without hydrophilic bumps contacted to the fog flow; \u003cstrong\u003e(f-g)\u003c/strong\u003e MD time-slides of the SLIPS with/without hydrophilic bumps when each system contains 1000 water molecules; \u003cstrong\u003e(h)\u003c/strong\u003e time-profiles of the surface adsorbed water molecules of the SLIPS with/without hydrophilic bumps according to the MD results.\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/a144c0b6af899b9dae982e5e.png"},{"id":75890196,"identity":"47fbc5ac-d686-49c5-a8d9-cf32b066031a","added_by":"auto","created_at":"2025-02-10 09:41:51","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1501964,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eMacro-design of the 3D fog collector and device.\u003c/strong\u003e \u003cstrong\u003e(a) \u003c/strong\u003eThe 2D patterned fog collector fabrication process; \u003cstrong\u003e(b) \u003c/strong\u003eWCR of the 2D patterned fog collector with different L and \u003cstrong\u003e(c)\u003c/strong\u003eθ values; \u003cstrong\u003e(d) \u003c/strong\u003ethe actual fog collection process of the optimal 2D patterned fog collector (fog flow at 100 mL/h) captured by high-speed camara; \u003cstrong\u003e(e)\u003c/strong\u003ecomparison of WCR between our work and other representative works (details of the references and experimental parameters were summarized \u003cstrong\u003eSupplementary Table S2\u003c/strong\u003e); \u003cstrong\u003e(f)\u003c/strong\u003e assembled 3D fog collection device and \u003cstrong\u003e(g)\u003c/strong\u003e its water collection performance (fog flow at 1500 mL/h); \u003cstrong\u003e(h)\u003c/strong\u003e the 3D fog collector could collect over 660 mL water within 500 min, and the sealed box was filled with collected water; \u003cstrong\u003e(i)\u003c/strong\u003e the preparation process of Cu-SHBL(Ti)-SLP sheet and \u003cstrong\u003e(j)\u003c/strong\u003e the corresponding SEM images, \u003cstrong\u003e(k)\u003c/strong\u003ethe lab-scale set-up of the water collection system synergistically integrated with organic pollutant degradation and\u003cstrong\u003e (l)\u003c/strong\u003e the results of the Rhodamine B degradation during fog collection (fog flow at 300 mL/h).\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/15f36e08a71bc1d0b8b6d0a4.png"},{"id":95362843,"identity":"f18b6ec6-7343-49c7-a5c3-61873b11dcba","added_by":"auto","created_at":"2025-11-07 08:08:07","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5641128,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/85c06451-28ed-45af-ad54-b0d541fae5ed.pdf"},{"id":75887999,"identity":"2bb5aed9-a9c5-4f59-b7bf-e1cc57877421","added_by":"auto","created_at":"2025-02-10 09:25:50","extension":"mp4","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":7023948,"visible":true,"origin":"","legend":"Supporting Information Video 1","description":"","filename":"SupportingInformationVideo1.mp4","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/1956d7a02db809b680c7d39e.mp4"},{"id":75888003,"identity":"0c2d1093-39e5-46ca-9f8f-4f1f3bbcb555","added_by":"auto","created_at":"2025-02-10 09:25:51","extension":"mp4","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":8432725,"visible":true,"origin":"","legend":"Supporting Information Video 2","description":"","filename":"SupportingInformationVideo2.mp4","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/4f1597cfee08047622a45824.mp4"},{"id":75888007,"identity":"e98db54f-dd33-4fa9-86af-a0b879aaa576","added_by":"auto","created_at":"2025-02-10 09:25:51","extension":"mp4","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":11642502,"visible":true,"origin":"","legend":"Supporting Information Video 3","description":"","filename":"SupportingInformationVideo3.mp4","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/5315a832ea0119bff8a851df.mp4"},{"id":75888015,"identity":"3bce969b-41eb-4014-bc07-d4da895de3f7","added_by":"auto","created_at":"2025-02-10 09:25:51","extension":"mp4","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":14176732,"visible":true,"origin":"","legend":"Supporting Information Video 4","description":"","filename":"SupportingInformationVideo4.mp4","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/44e916eea0d0fbb05d2bb590.mp4"},{"id":75888021,"identity":"08c94280-51f8-4655-940b-80452c1b4b97","added_by":"auto","created_at":"2025-02-10 09:25:52","extension":"docx","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":44614571,"visible":true,"origin":"","legend":"Supplementary Information","description":"","filename":"SupplementaryInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/88cb0568510fbb69902403e7.docx"},{"id":75888005,"identity":"f1d79a77-37c2-4dda-a302-3c4a939a7707","added_by":"auto","created_at":"2025-02-10 09:25:51","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":342741,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eScheme 1. The design of multi-bio-inspired SLIPS.\u003c/strong\u003e \u003cstrong\u003e(a)\u003c/strong\u003e Illustration of combining the Janus structure inspired by the desert beetle’s back carapace with the SLIPS inspired by the Nepenthes pitcher plant for fog collection. \u003cstrong\u003e(b)\u003c/strong\u003e Substrate preparation and lubricating oil infusion steps for SLIPS with exposed hydrophilic bumps.\u003c/p\u003e","description":"","filename":"Scheme1.png","url":"https://assets-eu.researchsquare.com/files/rs-5840260/v1/ae141fcbc78a1aed28a36eb3.png"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Preserving exposed hydrophilic bumps on multi-bioinspired slippery surface arrays unlocks high-efficiency fog collection and cleaning","fulltext":[{"header":"Introduction","content":"\u003cp\u003eWater scarcity remains one of the most critical challenges facing the global population, particularly in arid and semi-arid regions where conventional water sources are often limited\u003csup\u003e\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. In these areas, atmospheric water in the form of fog represents an underexploited resource that could significantly alleviate water shortages if effectively collected\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. The primary challenge of current fog harvesting systems lies in optimizing the nucleation vs. transportation balance of water droplets; these two processes are crucial for efficient water collection but are inherently contradictory in principle\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e,\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. On conventional large mesh nets made of woven polymer\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e,\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e, typically only one of these aspects can be optimized by adjusting the wettability, leaving it an unresolved dilemma.\u003c/p\u003e \u003cp\u003eInspired by nature\u0026rsquo;s unique structures and properties, innovative advancements in material surface and interface technologies have been made to enhance the water collection rate\u003csup\u003e\u003cspan additionalcitationids=\"CR10 CR11\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u003c/sup\u003e. One such innovation mimics the carapace of desert beetles\u003csup\u003e\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e, where an interlaced configuration of hydrophilic microstructures can easily capture tiny fog droplets until they grow large enough to roll off. This surface Janus structure undoubtedly accelerates the initial nucleation of water droplets. However, its alternating hydrophilic and hydrophobic surface distribution creates adhesion that hinders droplet detachment and surface migration\u003csup\u003e\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e,\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. Consequently, desert beetles need to tilt its body towards to the wind flow and the water droplets with the diameter of critical size could be transported to their mouths. Interestingly, nature also provides solutions to the problem of droplet transportation, pointing towards the construction of slippery liquid-infused porous surfaces (SLIPS)\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e, inspired by the water-slippery nature of peristome from the Nepenthes pitcher plant to hunt insects\u003csup\u003e\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. With only a certain angle of inclination, little droplets can be easily slid, transported, and collected by SLIPS. However, constructing stable SLIPS necessitates a superhydrophobic substrate infused with inert hydrophobic lubricating oil\u003csup\u003e\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e, which creates a significant water nucleation barrier, thus constraining the whole water collection rate.\u003c/p\u003e \u003cp\u003eGiven the limitations of these single bio-inspired structures in addressing either nucleation or transport, the key steps in fog harvesting, we propose that combining the characteristics of both structures could be an optimal solution. By constructing superhydrophobic SLIPS with exposed hydrophilic bumps on top, we can ideally balance the nucleation and transportation of water droplets (Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1a\u003c/span\u003e). However, a significant challenge is that, according to surface energy theories\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e, hydrophilic components are also inherently oleophilic in air. This means that during traditional lubricating oil infusion processes, the hydrophilic bumps are bound to be wrapped by oil. Thus, although much desired, achieving a stable superhydrophobic SLIPS with exposed hydrophilic top structures is extremely challenging.\u003c/p\u003e \u003cp\u003eIn this work, we developed an underwater lubricating oil infusion strategy for multi-bio-inspired SLIPS, preserving exposed hydrophilic bumps on the hydrophobic lubricating substrate (as illustrated in Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1b\u003c/span\u003e). This design facilitates rapid initial nucleation at hydrophilic bumps, combined with the efficient sliding transport of the formed water droplets, effectively solving the longstanding dilemma between nucleation and droplet transport.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSample fabrication and characteristic analysis\u003c/h2\u003e \u003cp\u003eInspired by the hydrophilic/hydrophobic hybrid microstructure on desert beetle back carapace, we designed a Janus structure of hydrophobic Cu(OH)\u003csub\u003e2\u003c/sub\u003e nanorods topped with hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e nanoparticles (Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1a\u003c/span\u003e\u003cb\u003e)\u003c/b\u003e via top interfacial growing (TIG) process (details of the preparation method see \u003cb\u003eSupplementary Figure \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003ea\u003c/b\u003e). The as-prepared Janus substrate was denoted as Cu-SHBL. Additionally, drawing inspiration from the water-slippery nature of the Nepenthes pitcher plant, we constructed SLIPS on the Cu-SHBL substrate via underwater lubricating oil infusion, which could preserve the exposed hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e bumps (Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1b\u003c/span\u003e, details of the preparation method see \u003cb\u003eSupplementary Figure \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003eb\u003c/b\u003e). For comparison, oil infusion was also conducted in air on the same substrate and served as a reference. Due to the superhydrophobic property of embedded fluorinated Cu(OH)\u003csub\u003e2\u003c/sub\u003e nanorods and the presence of hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e nanoparticles on top, a strong wetting gradient was formed. Therefore, during underwater oil infusion, water effectively encapsulated the hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e nanoparticles, allowing the lubricating oil to compactly and uniformly coat the substrate without contaminating the hydrophilic bumps and completely displacing air within the gaps of superhydrophobic nanorods, forming the Cu-SHBL-SLP film (Scheme \u003cspan refid=\"Sch1\" class=\"InternalRef\"\u003e1b\u003c/span\u003e). In contrast, oil-infusion in air not only contaminated the hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e nanoparticles but also left air gaps within the film. This was reflected as the change in the amount of infused lubricating oil, where underwater infused Cu-SHBL film has 22% higher oil infusion amount compared to the air-infused counterpart (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea), indicating that underwater infusion strategy is more effective in excluding air within the film and more conducive to even distribution of the lubricant (\u003cb\u003eSupplementary Figure S2\u003c/b\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAs a protective measure during the oil infusion process, the hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e bumps on top of the Cu-SHBL films were largely preserved and remained exposed, as observed in the different fog capture processes using Environmental Scanning Electron Microscopy (ESEM), shown in \u003cb\u003eSupplementary Figure S3 (\u003c/b\u003edetails of the process see \u003cb\u003eSupplementary Movie S1\u003c/b\u003e and \u003cb\u003e2)\u003c/b\u003e. Furthermore, the Cu-SHBL film infused underwater exhibited a smaller water contact angle but a larger water sliding angle compared to its air-infused counterpart (Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec), further confirmed the exposure of the on-top hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e nanoparticles. Typically, the loss of lubricating oil is the major limitation for long-term continuous applications of SLIPS\u003csup\u003e\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u003c/sup\u003e. Our underwater-infused SLIPS retained about 45.7% more lubricant than its air-infused counterpart after undergoing a spin process at 1500 rpm for 60 s (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed), which also demonstrated commendable stability during long-term fog collecting applications for over 20 runs (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ee). The underwater-infused Cu-SHBL-SLP with exposed hydrophilic bumps demonstrated 33.2% higher water collection rate (WCR) compared to its air-infused counterpart under the same experimental condition. This design featured exposed hydrophilic bumps on the hydrophobic SLIPS, which allowed the droplets to grow quickly and facilitates their removal. As illustrated in Figs.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ef and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eg, the underwater-infused Cu-SHBL-SLP showed a significantly larger critical droplet removal size of ~\u0026thinsp;1.116 mm, in contrast to the ~\u0026thinsp;0.642 mm observed with the air-infused version. Although the time to remove individual droplets had increased, this led to the accumulation of larger droplets over the same period, enhanced overall water collection rate.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eSurface wettability and water adhesion control\u003c/h3\u003e\n\u003cp\u003eFurthermore, we compared the WCR of various film stages\u0026mdash;Cu, Cu-SHL, Cu-SHB, Cu-SHBL, and Cu-SHBL-SLP (details of the various of films see \u003cb\u003eSupplementary Figure S6-S17\u003c/b\u003e) \u0026mdash;to confirm the effectiveness of our design, which incorporated exposed hydrophilic bumps on SLIPS for collecting fog (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea). Generally, the optimal scenario for fog-collection was featured by a shorter time and a heavier weight for the first droplet removal (FDR). We used a high-speed camera to measure the FDR time and weight across different films (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). Results showed that on the hydrophilic surfaces of Cu and Cu-SHL, although the FDR weight was very large (\u0026gt;\u0026thinsp;0.3g), the FDR time was significantly long (\u0026gt;\u0026thinsp;350 s) due to strong water adhesion. Following the hydrophobic treatment reduced surface adhesion to water, the Cu-SHB and Cu-SHBL films exhibited significantly shorter FDR times. However, the absence of water aggregation centers on superhydrophobic surface resulted in small first droplets, with the FDR weight less than 10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e g (These tiny droplets, too small to weigh, were estimated using magnified images during the water collection process, as detailed in the Supplementary \u003cb\u003eFigure S15\u003c/b\u003e and \u003cb\u003eS16\u003c/b\u003e). The introduction of underwater oil infusion on the Cu-SHBL-SLP film resulted in both a shorter FDR time and an FDR weight greater than 0.01g. This confirmed that the hydrophilic bumps on SLIPS acted as effective central sites for tiny water droplets capturing and coalescing. Detailed observations of the corresponding water collection process were available in the \u003cb\u003eSupplementary Figure S13-S17\u003c/b\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eBy adjusting the amount of BaSO\u003csub\u003e4\u003c/sub\u003e hydrophilic bumps on Cu-SHBL-SLP (details of the samples morphology see \u003cb\u003eSupplementary Figure S18\u003c/b\u003e), we identified the optimal hydrophilic bump loading at a Ba content of 0.53\u003csub\u003ewt\u003c/sub\u003e% (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec). Notably, before oil infusion, an increase in the number of BaSO\u003csub\u003e4\u003c/sub\u003e hydrophilic bumps led to greater adhesion of the Cu-SHBL to water droplets, which consequently increased the rolling angle of individual droplets (\u003cb\u003eSupplementary Figure S19\u003c/b\u003e and \u003cb\u003eS20\u003c/b\u003e). This trend of enhanced water adhesion not only persisted but intensified after underwater oil infusion, confirming that the our strategy effectively preserved the exposed hydrophilic bumps (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ed and \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee). Note that an excessive number of hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e bumps can even hinder the surface transport of water droplets, leading to a reduced WCR (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec). Using a high-speed camera, we observed the average droplet removal size on Cu-SHBL-SLP surfaces (positioned at 90 degrees) with varying numbers of BaSO\u003csub\u003e4\u003c/sub\u003e hydrophilic bumps and calculated corresponding water adhesion constants (\u003cb\u003eSupplementary Figure S21-24\u003c/b\u003e). Result showed that the adhesion constant of droplets to the film surface increases exponentially with the number of hydrophilic bumps, supporting our conclusions (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ef, \u003cb\u003eSupplementary Figure S23\u003c/b\u003e and \u003cb\u003eFigure S24\u003c/b\u003e). A comparison of Cu-SHBL-SLP films with different contents of hydrophilic bumps revealed that the sample with a 0.53\u003csub\u003ewt\u003c/sub\u003e% Ba content offers the optimal balance, resulting in the optimal FDR time and weight (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eg).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\n\u003ch3\u003eInitial capture and nucleation of water droplets from microscopic views\u003c/h3\u003e\n\u003cp\u003eExposed hydrophilic bumps enhanced adhesion to water molecules, which accelerated the capture and coalescence of water droplets. To substantiate this observation at the microscopic level, we monitored the dissociation of water molecules adsorbed on Cu-SHBL-SLP surfaces with varying hydrophilic bump contents (Ba content of 0\u0026thinsp;~\u0026thinsp;1.54\u003csub\u003ewt\u003c/sub\u003e%) using \u003cem\u003ein situ\u003c/em\u003e diffuse reflection infrared Fourier transform spectroscopy (DRIFTS). Under continuous water vapor flow, the DRIFTS spectra from different Cu-SHBL-SLP surfaces showed three types of infrared absorption bands located at 3447 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 3250 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, and 1644 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. These bands correspond to the dissociated water\u0026rsquo;s O-H stretching vibrations, water molecules\u0026rsquo; O-H stretching vibrations, and H-O-H bending vibration, respectively (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea). The results demonstrated that as the number of hydrophilic bumps increased, the efficiency of water molecule dissociation significantly improved (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb, \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec). This revealed that BaSO\u003csub\u003e4\u003c/sub\u003e hydrophilic bumps on SLIPS promoted the chemical dissociation equilibrium of water molecules, thereby increased water affinity and accelerated the formation of initial droplets and subsequent aggregation of fog droplets (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed, \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ee). An identical droplet formation process was also computationally simulated via molecular dynamics (MD) simulations. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ef, on SLIPS without hydrophilic bumps, water vapor, lacking aggregation centers, aggregated slowly and randomly in the groove on the substrate, formed the initial droplets over a 500 ps timescale. In contrast, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eg, the presence of exposed hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e bumps on SLIPS naturally served as centers of water molecule affinity. This allowed initial droplets to form and stabilize within 20\u0026ndash;30 ps, accelerated the process by more than a tenfold.\u003c/p\u003e\n\u003ch3\u003eFrom 2D patterns to 3D arrays\u003c/h3\u003e\n\u003cp\u003eLeveraging the characteristic of exposed hydrophilic bumps on SLIPS, we had further developed reverse Christmas tree-shaped Cu-SHBL-SLP patterns, inspired by desert cacti (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea). Through laser ablation, we precisely adjusted the length (L) and inclination angle (θ) of the serrated edges of the pattern templates (\u003cb\u003eSupplementary Figure S25\u003c/b\u003e and \u003cb\u003eS26)\u003c/b\u003e. This adjustment imparted unique Laplace pressures to the 2D sheet that influence the coalescence and transportation of water droplets\u003csup\u003e\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e (Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed, \u003cb\u003eSupplementary Movie S3\u003c/b\u003e). This distinctive patterned structure facilitated the coalescence and transportation of multiple droplets within ~\u0026thinsp;72 s, which was four times faster than the pristine, unpatterned Cu-SHBL-SLP film (\u0026gt;\u0026thinsp;285 s). In this structure, the length L should not be overly long. An appropriate L provided sufficient Laplace pressure to aid water movement, but an excessively high L increased the transportation distance of the droplets from the tip to the base, thereby added unnecessary time for droplet coalescence in the central channel (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb). The inclination angle θ was also important; generally, the smaller the θ, the greater the combined effect of gravity and Laplace forces, enhanced the efficiency of droplet coalescence and transportation. When θ exceeded 90 degrees, gravity counteracted the Laplace pressure. However, within a range of θ\u0026thinsp;=\u0026thinsp;30\u0026thinsp;~\u0026thinsp;60 degrees, an increase in θ benefited the initial fog capture process, making θ\u0026thinsp;=\u0026thinsp;60 degrees the optimal parameter for WCR (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec). This optimization is based on the observation that a smaller inclination angle impeded the initial fog capture along the span direction, negatively affected the WCR (\u003cb\u003eSupplementary Figure S27\u003c/b\u003e and \u003cb\u003eMovie S4\u003c/b\u003e). Under the conditions of L\u0026thinsp;=\u0026thinsp;1 cm and θ\u0026thinsp;=\u0026thinsp;60 degrees, the patterned Cu-SHBL-SLP achieved the WCR over 5000 mg/cm\u0026sup2; h at 300 mL/h and reached up to 60000 mg/cm\u0026sup2; h at 1500 mL/h, marked the highest water collection performance reported to date with fog flow outputs ranging from 420 to 1500 mL/h (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ee). Note that water collection performance was largely depended on the water content in the ambient fog environment. Our analysis only compared the top 20 representative fog collection systems with clearly specified fog flow conditions and no external energy input (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ee and \u003cb\u003eSupplementary Table S2\u003c/b\u003e), and our system surpassed all previously reported systems when the output fog flow exceeded 420 mL/h. Furthermore, inspired by the fog collection enhancement effect observed in densely arrayed plants in the forest\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e, we constructed an integrated fog collection device by assembling 2D patterned sheet into densely arranged 3D arrays to maximize the extraction of moisture from the air (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ef). The sealed box beneath the arrays served as storage to minimize loss from volatilization. The fog collection device consistently collected more than 660 g of water within 500 min (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eg and Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eh).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eMoreover, considering the dual challenges of water scarcity and pollution, integrating water collection with purification processes addresses two critical environmental issues simultaneously. This approach is particularly vital in regions affected by both limited water resources and high levels of atmospheric pollutants, such as the volatile organic compounds (VOCs), environmental pesticide residues, and other organic pollutants, can lead to the contamination of collected water, rendering the limitation of direct use\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e,\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e. Traditional methods of water purification often require extensive infrastructure and significant energy inputs, which are not always feasible in remote or economically disadvantaged areas. By developing systems that can both collect and purify fog, we can harness naturally occurring water sources and ensure that the water is safe for consumption and other uses immediately upon collection\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. Leveraging the unique structure of hydrophilic bumps on SLIPS, hydrophilic photocatalysts, i.e., TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles, widely used in photocatalytic water pollution remediation\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e, can easily adhere to the hydrophilic bumps due to similar wettability, thereby endowing these exposed tips with photocatalytic water purification capabilities (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ei and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ej). By placing as-prepared Cu-SHBL(Ti)-SLP film under UV light illumination, tiny fog droplets are purified by a significant amount of reactive oxygen species (ROS) generated during the initial capture and nucleation process by the TiO\u003csub\u003e2\u003c/sub\u003e nanoparticles. These tiny initial droplets also act as microreactors with a high gas-liquid exchange capacity and enhanced local ROS concentration, thus, their purification effect is usually more efficient than in bulk water\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e. We investigated the photocatalytic purification capacity of the TiO\u003csub\u003e2\u003c/sub\u003e-topped SLIPS sheet by adding the representative organic dye (Rhodamine B) pollution to the fog sources to simulate the photodegradation of organic pollutants during collection under UV irradiation, and the results showed that the dye molecules in the collected water were completely degraded without any residue (verified by both the photo images and UV-vis spectrophotometer). More importantly, during this process, the water collection performance of the SLIPS films was not compromised (\u003cb\u003eSupplementary Figure S28\u003c/b\u003e), confirming the high efficiency of this design in both water collection and purification.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis work of ours, from the microscopic to the macroscopic, developed a comprehensive solution to water sustainability by combining multiple bioinspired designs (desert beetle back, pitcher plant slippery surface, cactus patterned structure and densely arrayed plants) with advanced material science. By maintaining the structure of hydrophilic bumps on SLIPS and integrating TiO\u003csub\u003e2\u003c/sub\u003e photocatalysts, our system efficiently collects and purifies fog, gathering over 660 grams of water in 500 min. The key to this design is the successful preservation of the exposed hydrophilic bumps through underwater lubricant-oil infusion process, which resolves the longstanding dilemma of the nucleation vs. transportation balance in the field. This breakthrough ensures strong nucleation capabilities along with efficient transportation, thus achieving record-breaking water collection results under mid-to-high fog flow condition (420\u0026thinsp;~\u0026thinsp;1500 mL/h). The future perspective of this work aims to scale and refine this technology, enhancing its application potential through the development of portable, energy-efficient, and cost-effective products.\u003c/p\u003e "},{"header":"Experimental section","content":"\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003eChemicals\u003c/h2\u003e \u003cp\u003eCopper sheet (0.1 mm) was purchased from Biling factory. 1H,1H,2H,2H-Perfluorooctyltriethoxysilane (PFTS) was obtained from Bidepharm. Sodium hydroxide (NaOH), ammonium persulfate ((NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003eS\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e8\u003c/sub\u003e), barium chloride (BaCl\u003csub\u003e2\u003c/sub\u003e), potassium sulphate (K\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e), ethanol and acetone were purchased from Sinopharm Chemical Reagent Co., Ltd. Polyperfluoromethylisopropyl ether (PFPE) were gained from Aladdin Reagent Co. Deionized water (DI water) was applied in all the experimental processes. All the chemicals were applied without any other purification.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e\n\u003ch3\u003ePreparation of Cu-SHBL film\u003c/h3\u003e\n\u003cp\u003eThe original copper sheet (20 mm \u0026times; 20 mm) was first washed with detergent, acetone, ethanol and DI water respectively. Then the cleaned Cu sheet was immerged into the mixed solution containing 2.5 m NaOH and 0.13 m (NH\u003csub\u003e4\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003eS\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e8\u003c/sub\u003e for 15 min to obtain the Cu/Cu(OH)\u003csub\u003e2\u003c/sub\u003e, named as Cu-SHL. To endow the water-repellent ability, the Cu-SHL was immerged into the PFTS ethanol solution and dried at 50℃ in air, which was named as Cu-SHB. Then, the superhydrophobic nanorods with hydrophilic particles on its top was achieved via unique top interfacial growth (TIG) process. Firstly, the superhydrophobic Cu-SHB was clamped by two glass tubes with the diameter of 1.5 cm. Then 0.1 m BaCl\u003csub\u003e2\u003c/sub\u003e aqueous solution was poured into the glass tube above. The aqueous solution could not wet the beneath sheet and kept a Cassie state due to the low surface energy and high roughness of the fluorinated Cu(OH)\u003csub\u003e2\u003c/sub\u003e nanorod arrays. The superhydrophobic nanorods could prevent the sheet to be wetted while only the top of nanorods could contact to the aqueous solution, which provided a feasible strategy to realize the top modification. A dropper with 0.1 m K\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e aqueous solution was forced into the above aqueous solution and ejected onto the top surface of Cu-SHB. Consequently, the BaSO\u003csub\u003e4\u003c/sub\u003e sediment could be formed on the nanorods, and regarded as the Cu-SHBL film.\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eUnderwater lubricating oil infusion process\u003c/h2\u003e \u003cp\u003eTo construct the slippery liquid-infused porous surface (SLIPS), PFPE was selected as the lubricating oil and conducted the underwater oil infusion process. Firstly, the prepared Cu-SHBL film was placed into the bottom of Petri dish filled with DI water under the external forced. Then 500 \u0026micro;L PFPE was taken by a pipette gun and dropped onto the Cu-SHBL film surface, realized the underwater lubricating oil infusion process. After placed in water for 10 min, the sheet was vertically dried at room temperature overnight. And the obtained sheet was named as Cu-SHBL-SLP. To make a comparation, the Cu-SHB was as the substrate and conducted the underwater lubricating oil infusion process, which was named as Cu-SHB-SLP.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eWater harvesting measurement\u003c/h2\u003e \u003cp\u003eThe water harvesting process of the prepared material was evaluated by the homemade testing system. The fog flow with 300\u0026ndash;1500 mL/h was provided by the ultrasonic humidifier\u003csup\u003e\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u003c/sup\u003e (YADU ultrasonic humidifier YC\u0026thinsp;\u0026minus;\u0026thinsp;D205, China and AUX mechanical standards, Hefei Hemei E-commerce Co., Ltd.). The temperature and relative humidity (RH) were 20\u0026deg;C and 90%, respectively. All the studied meshes were clamped on a holder with a fixed distance of 6 cm to the humidifier nozzle, and all the valid collection areas of the meshes were 3.14 cm\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e for 2D sheet and different valid area for 3D patterned sheet. Without any further illustration, the fog flow was normally perpendicular to the mesh surface. The collected water was stored using a self-made container, and the mass of the collected water was calculated every 10 min. The water collection mass (WCM) was calculated with the following equation:\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:WCM=\\frac{M}{A}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere M (mg) is the amount of the collected water and A (cm\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e) is the valid area of the meshes. The water collection rate (WCR) was calculated with the following equation:\u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e\n$$\\:\\text{W}\\text{C}\\text{R}=\\frac{WCM}{t}=\\frac{M}{A\\times\\:t}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e2\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere t (h) is the experimental time of fog collection.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eLubricating oil obtain/loss tests\u003c/h2\u003e \u003cp\u003eThe lubricating oil obtain was determined by the weight of samples before and after the lubricating oil infusion process. The lubricating oil obtain could be calculated as follows:\u003cdiv id=\"Equ3\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ3\" name=\"EquationSource\"\u003e\n$$\\:\\text{L}\\text{u}\\text{b}\\text{r}\\text{i}\\text{c}\\text{a}\\text{t}\\text{i}\\text{n}\\text{g}\\:\\text{o}\\text{i}\\text{l}\\:\\text{o}\\text{b}\\text{t}\\text{a}\\text{i}\\text{n}\\:\\left(\\%\\right)=\\frac{{M}_{ob}-{M}_{oa}}{{M}_{ob}}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere M\u003csub\u003eob\u003c/sub\u003e (g) was the weight of the material before lubricating oil, M\u003csub\u003eoa\u003c/sub\u003e (g) was the weight of the material after lubricating oil. Due to the superoleophilic property of superhydrophobic Cu-SHB, the lubricating oil obtain test was conducted on two sides.\u003c/p\u003e \u003cp\u003eThe lubricating oil loss was determined by the weight of samples before and after the spin process or the fog collection test. The lubricating oil loss could be calculated as follows:\u003cdiv id=\"Equ4\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ4\" name=\"EquationSource\"\u003e\n$$\\:\\text{L}\\text{u}\\text{b}\\text{r}\\text{i}\\text{c}\\text{a}\\text{t}\\text{i}\\text{n}\\text{g}\\:\\text{o}\\text{i}\\text{l}\\:\\text{l}\\text{o}\\text{s}\\text{s}\\:\\left(\\%\\right)=\\frac{{M}_{lb}-{M}_{la}}{{M}_{lb}}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e4\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere M\u003csub\u003elb\u003c/sub\u003e (g) was the weight of the material before tests, M\u003csub\u003ela\u003c/sub\u003e (g) was the weight of the material after tests.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eMD simulations\u003c/h2\u003e \u003cp\u003eIn this work, the classical molecular dynamics simulation method\u003csup\u003e\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u003c/sup\u003e is used to study the water adsorption properties of SLIPS in two different microscopic structure, i.e., with hydrophilic BaSO\u003csub\u003e4\u003c/sub\u003e particles and without BaSO\u003csub\u003e4\u003c/sub\u003e components. The molecular structure of PFPE monomer unit and whole PFPE components are shown in the \u003cb\u003eSupplementary Figure S29a\u003c/b\u003e and \u003cb\u003eb\u003c/b\u003e. And the substrate contains 100 PFPE molecules as shown in \u003cb\u003eSupplementary Figure S29c\u003c/b\u003e. 1000 water molecules were randomly placed above the substrate, as shown in \u003cb\u003eSupplementary Figure S30a\u003c/b\u003e, and BaSO\u003csub\u003e4\u003c/sub\u003e nanoparticle is placed between the water and the substrate in one simulation system as shown in \u003cb\u003eSupplementary Figure S30b\u003c/b\u003e. Both the initial configurations of solvent systems were constructed through the software of Material Studio, all the molecules were randomly inserted in a simulation box.\u003c/p\u003e \u003cp\u003eThe xy direction is set as periodic boundary conditions to characterize xy orientation as infinite in size. The molecular force field is consisted of nonbonded and bonded interaction. The nonbonded interaction contains van deer Waals (vdW) and electrostatic interaction, which is described by Eq.\u0026nbsp;\u003cspan refid=\"Equ5\" class=\"InternalRef\"\u003e5\u003c/span\u003e and Eq.\u0026nbsp;\u003cspan refid=\"Equ6\" class=\"InternalRef\"\u003e6\u003c/span\u003e, respectively. The function equations are as follows:\u003cdiv id=\"Equ5\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ5\" name=\"EquationSource\"\u003e\n$$\\:{E}_{LJ}\\left({r}_{ij}\\right)=4{\\epsilon\\:}_{ij}\\left({\\left(\\frac{{\\epsilon\\:}_{ij}}{{r}_{ij}}\\right)}^{12}-{\\left(\\frac{{\\epsilon\\:}_{ij}}{{r}_{ij}}\\right)}^{6}\\right)$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e5\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Equ6\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ6\" name=\"EquationSource\"\u003e\n$$\\:{E}_{c}\\left({r}_{ij}\\right)=\\frac{{q}_{i}{q}_{j}}{4\\pi\\:{\\epsilon\\:}_{o}{\\epsilon\\:}_{r}{r}_{ij}}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e6\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eFor different kinds of atoms, the Lorentz-Berthelot mix rules were adopted for vdW interactions, which is following the Eq.\u0026nbsp;\u003cspan refid=\"Equ7\" class=\"InternalRef\"\u003e7\u003c/span\u003e:\u003cdiv id=\"Equ7\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ7\" name=\"EquationSource\"\u003e\n$$\\:{\\sigma\\:}_{ij}=\\frac{1}{2}\\left({\\sigma\\:}_{ii}+{\\sigma\\:}_{jj}\\right);{\\epsilon\\:}_{ij}={\\left({\\epsilon\\:}_{ii}*{\\epsilon\\:}_{jj}\\right)}^{\\frac{1}{2}}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e7\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003eThe cutoff distance of vdW and electronic interactions was set to 1.0 nm.\u003c/p\u003e \u003cp\u003eFor each simulation, an energy minimization was firstly employed to relax the simulation box. Then, a canonical (NVT) ensemble with the 1 fs time step is employed to optimized the simulation box, where the temperature is set as 273 K. The temperature is kept via the Nose-Hoover thermostat. The NVT optimization time was set to 1.0 ns, which is enough long to obtain a stable box size. During the relaxation process, restricting the adsorption of water molecules on the substrate. At last, another 0.5 ns NVT simulation was performed to adsorbed water molecules. In all the MD simulation, the motion of atoms was described by classical Newton\u0026rsquo;s equation, which was solved using the velocity-Verlet algorithm, and the simulation program is carried out by the large-scale simulation software LAMMPS 1 developed by the National Laboratory of the United States.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eCharacterization devices\u003c/h2\u003e \u003cp\u003eThe scanning electron microscopy (SEM, JSM-7800F, Hitachi, Japan) equipped with the energy-dispersive spectroscope (EDS) was used to study the surface morphology and structure. The environmental scanning electron microscope (ESEM, QUANTA200) was applied to study the water capture process of the prepared samples surface. The UV-visible spectrophotometer (Agilent Cary 8454) was used to test the organic pollution contents. The surface wettability was observed by the contact angle meter (LAUDA Scientific, China). The water droplet adhesive force of the sample surface was conducted via the Surface Tension Measuring Instrument (Kruss K100, German). Fourier transform infrared spectrometer (Nicolet Nexus 470, America), X-ray diffraction (XRD-6100, Japan) and X-ray photoelectron spectroscopy (XPS, Escalab 250Xi, America) were tested to analyze the chemical components and surface functional groups of the sample. In-situ diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) experiments were performed on a Thermo Nicolet iS10 spectrometer equipped with a mercury cadmium telluride (MCT) detector to study the dissociation of water molecules adsorbed on the prepared samples surface during fog collection process.\u003c/p\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAcknowledgments\u003c/h2\u003e \u003cp\u003eThis work was financially supported by the National Natural Science Foundation of China (Nos. 22378173) and Graduate Research Innovation Program of Jiangsu Provincial (KYCX23_3648).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eTrenberth KE et al (2013) Global warming and changes in drought. Nat Clim Change 4:17\u0026ndash;22. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nclimate2067\u003c/span\u003e\u003cspan address=\"10.1038/nclimate2067\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMekonnen MM, Hoekstra AY (2016) Four billion people facing severe water scarcity. Sci Adv 2:e1500323. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1126/sciadv.1500323\u003c/span\u003e\u003cspan address=\"10.1126/sciadv.1500323\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLord J et al (2021) Global potential for harvesting drinking water from air using solar energy. Nature 598:611\u0026ndash;617. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41586-021-03900-w\u003c/span\u003e\u003cspan address=\"10.1038/s41586-021-03900-w\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKlemm O et al (2012) Fog as a Fresh-Water Resource: Overview and Perspectives. Ambio 41:221\u0026ndash;234. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s13280-012-0247-8\u003c/span\u003e\u003cspan address=\"10.1007/s13280-012-0247-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang Y et al (2024) Improved Water Collection from Short-Term Fog on a Patterned Surface with Interconnected Microchannels. Environ Sci Technol 58:3812\u0026ndash;3822. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.est.3c09504\u003c/span\u003e\u003cspan address=\"10.1021/acs.est.3c09504\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLu H et al (2022) Materials Engineering for Atmospheric Water Harvesting: Progress and Perspectives. \u003cem\u003eAdv Mater\u003c/em\u003e, e2110079. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/adma.202110079\u003c/span\u003e\u003cspan address=\"10.1002/adma.202110079\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSchemenauer RS, Cereceda PA (1994) Proposed Standard Fog Collector for Use in High-Elevation Regions. J Appl Meteorol Climatology 33:1313\u0026ndash;1322. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1175/1520-0450(1994)033\u0026lt;1313:APSFCF\u0026gt;2.0.CO;2\u003c/span\u003e\u003cspan address=\"10.1175/1520-0450(1994)033%3C1313:APSFCF%3E2.0.CO;2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFernandez DM et al (2018) Fog Water Collection Effectiveness: Mesh Intercomparisons. Aerosol Air Qual Res 18:270\u0026ndash;283. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.4209/aaqr.2017.01.0040\u003c/span\u003e\u003cspan address=\"10.4209/aaqr.2017.01.0040\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZheng Y et al (2010) Directional water collection on wetted spider silk. Nature 463:640\u0026ndash;643. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nature08729\u003c/span\u003e\u003cspan address=\"10.1038/nature08729\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJu J et al (2012) A multi-structural and multi-functional integrated fog collection system in cactus. Nat Commun 3:1247. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/ncomms2253\u003c/span\u003e\u003cspan address=\"10.1038/ncomms2253\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen H et al (2018) Ultrafast water harvesting and transport in hierarchical microchannels. Nat Mater 17:935\u0026ndash;942. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41563-018-0171-9\u003c/span\u003e\u003cspan address=\"10.1038/s41563-018-0171-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePark KC et al (2016) Condensation on slippery asymmetric bumps. Nature 531:78\u0026ndash;82. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nature16956\u003c/span\u003e\u003cspan address=\"10.1038/nature16956\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eParker AR, Lawrence CR (2001) Water capture by a desert beetle. Nature 414:33\u0026ndash;34. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/35102108\u003c/span\u003e\u003cspan address=\"10.1038/35102108\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJi Y et al (2024) Nanoscale Drag Reduction Effect Enables Efficient Fog Harvesting. Adv Funct Mater. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/adfm.202411083\u003c/span\u003e\u003cspan address=\"10.1002/adfm.202411083\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang Y et al (2022) Sustainable Superhydrophobic Surface with Tunable Nanoscale Hydrophilicity for Water Harvesting Applications. Angew Chem Int Ed 61. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/anie.202115238\u003c/span\u003e\u003cspan address=\"10.1002/anie.202115238\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWong TS et al (2011) Bioinspired self-repairing slippery surfaces with pressure-stable omniphobicity. Nature 477:443\u0026ndash;447. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nature10447\u003c/span\u003e\u003cspan address=\"10.1038/nature10447\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen H et al (2016) Continuous directional water transport on the peristome surface of Nepenthes alata. Nature 532:85\u0026ndash;89. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/nature17189\u003c/span\u003e\u003cspan address=\"10.1038/nature17189\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSu B, Tian Y, Jiang L (2016) Bioinspired Interfaces with Superwettability: From Materials to Chemistry. J Am Chem Soc 138:1727\u0026ndash;1748. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/jacs.5b12728\u003c/span\u003e\u003cspan address=\"10.1021/jacs.5b12728\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeng R et al (2020) A Bioinspired Slippery Surface with Stable Lubricant Impregnation for Efficient Water Harvesting. ACS Appl Mater Interfaces 12:12373\u0026ndash;12381. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acsami.0c00234\u003c/span\u003e\u003cspan address=\"10.1021/acsami.0c00234\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen Y et al (2020) Bioinspired Superwettable Microspine Chips with Directional Droplet Transportation for Biosensing. ACS Nano 14:4654\u0026ndash;4661. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acsnano.0c00324\u003c/span\u003e\u003cspan address=\"10.1021/acsnano.0c00324\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDawson TE (1998) Fog in the California redwood forest: ecosystem inputs and use by plants. Oecologia 117:476\u0026ndash;485. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s004420050683\u003c/span\u003e\u003cspan address=\"10.1007/s004420050683\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGhosh R et al (2023) Photocatalytically reactive surfaces for simultaneous water harvesting and treatment. Nat Sustain 6:1663\u0026ndash;1672. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41893-023-01159-9\u003c/span\u003e\u003cspan address=\"10.1038/s41893-023-01159-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGhosh R, Sahu RP, Ganguly R, Zhitomirsky I, Puri IK (2020) Photocatalytic activity of electrophoretically deposited TiO2 and ZnO nanoparticles on fog harvesting meshes. Ceram Int 46:3777\u0026ndash;3785. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.ceramint.2019.10.100\u003c/span\u003e\u003cspan address=\"10.1016/j.ceramint.2019.10.100\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhu H et al (2021) Integration of water collection and purification on cactus- and beetle-inspired eco-friendly superwettable materials. Water Res 206. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.watres.2021.117759\u003c/span\u003e\u003cspan address=\"10.1016/j.watres.2021.117759\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSang L, Zhao Y, Burda C (2014) TiO2Nanoparticles as Functional Building Blocks. Chem Rev 114:9283\u0026ndash;9318. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/cr400629p\u003c/span\u003e\u003cspan address=\"10.1021/cr400629p\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGe Q et al (2023) Significant Acceleration of Photocatalytic CO2 Reduction at the Gas-Liquid Interface of Microdroplets**. Angew Chem Int Ed 62. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/anie.202304189\u003c/span\u003e\u003cspan address=\"10.1002/anie.202304189\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDi H, Wang Z, Hua D (2019) Precise size distribution measurement of aerosol particles and fog droplets in the open atmosphere. Opt Express 27:A890\u0026ndash;A908. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1364/OE.27.00A890\u003c/span\u003e\u003cspan address=\"10.1364/OE.27.00A890\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePlimpton SJ (1993) Fast parallel algorithms for short-range molecular dynamics. J Comput Phys 117:1\u0026ndash;19. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1006/JCPH.1995.1039\u003c/span\u003e\u003cspan address=\"10.1006/JCPH.1995.1039\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Schemes","content":"\u003cp\u003eScheme 1 is available in the Supplementary Files section\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"nature-portfolio","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"","title":"Nature Portfolio","twitterHandle":"","acdcEnabled":false,"dfaEnabled":false,"editorialSystem":"ejp","reportingPortfolio":"","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-5840260/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5840260/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe efficiency of fog water collection technologies is inherently hindered by the long-standing dilemma of nucleation vs. transportation balance. Inspired by nature, we address this issue by preserving hydrophilic bumps on slippery liquid-infused porous surfaces (SLIPS) through an underwater infusion strategy, creating a super-slippery fog collector with multi-scale biomimetic structures. This surface combines features from beetle carapaces and pitcher plant surfaces, enabling rapid initial nucleation on hydrophilic bumps and efficient droplet transport. As a result, we have developed the most efficient fog collecting surface reported to date, capturing 5000\u0026ndash;60000 mg/cm\u0026sup2; per hour with fog flow rates ranging from 300\u0026ndash;1500 mL/h. By macroscopically scaling and optimizing, we have constructed an integrated 3D fog collecting device capable of capturing over 660 g of water in 500 minutes. Further integrating TiO\u003csub\u003e2\u003c/sub\u003e into the bumps imparts the ability for simultaneous water collection and purification without sacrificing collection efficiency. Our work reveals that resolving the nucleation-transport dichotomy is key to achieving high-efficiency fog water collection.\u003c/p\u003e","manuscriptTitle":"Preserving exposed hydrophilic bumps on multi-bioinspired slippery surface arrays unlocks high-efficiency fog collection and cleaning","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-02-10 09:25:43","doi":"10.21203/rs.3.rs-5840260/v1","editorialEvents":[],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"nature-communications","isNatureJournal":true,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"NCOMMS","sideBox":"Learn more about [Nature Communications](http://www.nature.com/ncomms/)","snPcode":"","submissionUrl":"https://mts-ncomms.nature.com/","title":"Nature Communications","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature Communications","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"7e889244-3d00-4520-b060-6ee98309d0ad","owner":[],"postedDate":"February 10th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":44006174,"name":"Earth and environmental sciences/Environmental sciences/Environmental chemistry"},{"id":44006175,"name":"Physical sciences/Chemistry/Energy"},{"id":44006176,"name":"Physical sciences/Energy science and technology/Energy harvesting/Devices for energy harvesting"},{"id":44006177,"name":"Physical sciences/Chemistry/Green chemistry/Sustainability"},{"id":44006178,"name":"Physical sciences/Chemistry/Surface chemistry"}],"tags":[],"updatedAt":"2025-11-07T08:07:59+00:00","versionOfRecord":{"articleIdentity":"rs-5840260","link":"https://doi.org/10.1038/s41467-025-65169-1","journal":{"identity":"nature-communications","isVorOnly":false,"title":"Nature Communications"},"publishedOn":"2025-11-06 05:00:00","publishedOnDateReadable":"November 6th, 2025"},"versionCreatedAt":"2025-02-10 09:25:43","video":"","vorDoi":"10.1038/s41467-025-65169-1","vorDoiUrl":"https://doi.org/10.1038/s41467-025-65169-1","workflowStages":[]},"version":"v1","identity":"rs-5840260","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5840260","identity":"rs-5840260","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}