Multiscale Prototyping Approach via In-situ Switching Electrohydrodynamics for Flexible Microfluidic Design

Microfluidic devices are critical in lab-on-chip, drug delivery, flexible sensors, etc. However, a formidable challenge remains in fabricating microfluidic channels with complex shapes during design and verification. Herein, we present a facile approach for manufacturing polystyrene (PS) templates by in-suit combining microscale electrohydrodynamic (EHD) printing and mesoscale direct ink writing (DIW). The desired multiscale filament width from 20 μm to > 1 mm could be obtained through appropriate voltage and pressure with continuous printing. The further process parameters for adjusting line width including deposition speed, auxiliary heating for DIW/EHD printing mode were investigated detailly. And we prove the stability and feasibility for producing microfluidics via the method by AFM, EDS and filling test. Based on the solubility of PS in the organic solvent, we can readily reconfigure the existing template by erasing and printing part of the patterns for better remanufacturing. Finally, the LM-filling PDMS microfluidic is experimented to demonstrate the future potential and advantage of the printing technology for fabricating the flexible microfluidic device. Graphical Abstract