Versatile and low-cost fabrication of modular lock-and-key micro-fluidics for integrated connector mixer using a stereolithography 3D printing

Abstract We present a low-cost and simple method to fabricate microfluidic modules directly on a submillimeter scale utilizing an economic stereolithography (SLA) three-dimensional (3D) printer, which only costs less than 400 USD for the investment. The proposed study is promising for a high throughput fabrication module, typically limited by conventional microfluidic fabrications, such as photolithography and polymer casting methods. We demonstrate the two lock-and-key modular fluidic platforms for connector modules and chamber modules with optimized parameters, such as exposure condition and printing orientation. In addition, optimization of post-processing was performed to investigate the reliability of the fabricated hollow structures, which are fundamental to creating a fluidic channel or chamber. We found out that by using an inexpensive 3D printer, the fabricated resolution can be pushed down to 850 µm and 550 µm size for squared- and circled-shaped, respectively; by the gradual hollow structure, applying vertical printing orientation. These strategies opened up the possibility of developing straightforward microfluidic platforms that could replace conventional microfluidics mold fabrication methods, such as photolithography and milling, which are costly and time-consuming. Considerably cheap commercial resin and its tiny volume employed for a single printing procedure extremely cut down the estimated fabrication cost to less than 50 cents USD/module. The simulation study unravels the prominent properties of the fabricated devices for biological fluid mixers such as plasma blood. This study is eminently prospective toward microfluidics application in clinical biosensing, where disposable, low-cost, high-throughput, and reproducible chips are highly required.