A Three-Dimensional Liquid-Based Exchangeable Gradient Osmosis Chip for a Permeability Controllable Microfluidic Device

3D printing technology has significant potential for use in the field of microfluidics. Microfluidic chips are biochips that have been applied in biomedical areas such as disease diagnosis and drug delivery in vivo. However, traditional 2D manufacturing techniques limit the scope of their fabrication and usage. In addition, membrane-embedded microfluidic chips need intricately designed structures and well-defined nanofiber membranes for delivering specific drugs and filtering out impurities from blood, and it is difficult to respond quickly to the design and production of these complex three-dimensional shapes. Herein, we introduce a liquid-based exchangeable gradient osmosis (LEGO) chip comprising a 3D structured channel printed via a digital light processing system within 10 min and an electrospun nanofiber membrane. The attachment conditions of the nanofiber membranes to the 3D channel were optimized, while the permeability of specific materials was controlled by adjusting the concentration of nanofibers and the flow speed through the 3D channel. We anticipate that the LEGO chip will be used to produce bio-applicable devices for mass transfer in vivo.