Fabrication of microfluidic chips using controlled dissolution of 3D printed scaffolds

Microfluidic chips are commonly fabricated using soft lithography, which often requires a clean room and micropatterning equipment. Recently, microfluidic chips are increasingly fabricated using 3D printing, but this technology is still limited in smallest channel printability, transparency, supports residue, and biocompatibility. In this work, a simple, fast, and inexpensive step is introduced to fabricate polydimethylsiloxane (PDMS) microfluidic chips using enhanced internal scaffold removal (eISR). It is found that final channel dimension decreases by 0.22 +/- 0.02 mu m/revolution with a 7% error using eISR. Surface topology is inspected after dissolution using scanning electron microscopy. A T-junction device, bifurcation channels, and curved channels are fabricated to demonstrate the usability of eISR in multiple applications. Compared to previous methods, eISR provides acrylonitrile-butadiene-styrene dissolution before PDMS casting to achieve thinner and smoother channels produced using a commercial 3D printer.