Abstract

Advances in 3D Printing for Microfluidics

Gregory Nordin, Professor, Brigham Young University

While there is great interest in 3D printing for microfluidic device fabrication, a main challenge has been to achieve feature sizes that are in the truly microfluidic regime (<100 µm). A key issue is that microfluidic devices are comprised primarily of negative space features, which therefore dominate 3D printing resolution requirements, as compared to positive space features that are typical for many other 3D printing applications. Consequently, we have developed our own stereolithographic 3D printers and materials that are specifically tailored to meet these needs. We have shown 3D printed channels as small as 18 µm x 20 µm, and have recently reduced this to 2 µm x 2 µm. We have also developed active elements such as valves and pumps with the smallest valves having an active area of only 15 µm x 15 µm. With these capabilities, we demonstrate highly integrated 3D printed microfluidic components such as a 10-stage 2-fold serial dilutor in an X-Y footprint of only 2.2 mm x 1.1 mm. We also show a fast (~1 ms) and small (<1 mm^3) 3D printed mixer using a new multi-resolution 3D printing technique. These advances open the door to 3D printing as a replacement for expensive cleanroom fabrication processes, with the additional advantage of fast (~5-15 minute), parallel fabrication of many devices in a single print run due to their small size.