Braiding Three‐Dimensional Paper‐Based Microfluidic Devices

Three‐dimensional paper‐based microfluidic devices have great potential in various applications, including point‐of‐care diagnostics, environmental monitoring, and tissue engineering. However, their fabrication is still limited to stacking and origami methods, in which auxiliary equipment is needed to maintain the layers in tightly connected junctions. Inspired by the art of bamboo braiding in China, we developed a novel fabrication technique based on the braiding concept to create three‐dimensional paper‐based microfluidic devices with PDMS‐impregnated paper substrates as the building units. The resulting three‐dimensional paper device brings unique advantages, including compactness, facile disassembly, and real‐time flow visualization. The multiplexed glucose analysis with a braided device integrated with 16‐switchable valves for flow control was further fabricated to demonstrate the device's applicability. We envision braiding‐based fabrication technology opening new possibilities and bringing broad applications for three‐dimensional paper microfluidic devices.