Abstract

Microfluidics’ New Wave: Digitally-Fabricated Microdevices

Albert Folch, Professor of Bioengineering, University of Washington

The vast majority of microfluidic devices are presently manufactured using micromolding processes that work very well for a reduced set of biocompatible materials, but the time, cost, and design constraints of micromolding hinder the commercialization of many devices. PDMS, in particular, is extremely popular in academic labs, yet the fabrication procedures are based on cumbersome manual methods and the material itself strongly absorbs lipophilic drugs. As a result, the dissemination of many cell-based microfluidic chips – and their impact on society – is in jeopardy. Digital Manufacturing (DM) is a family of computer-centered processes that integrate digital 3D designs, automated (additive or subtractive) fabrication, and device testing in order to increase fabrication efficiency. Importantly, DM enables the inexpensive realization of 3D designs that are impossible or very difficult to mold. The adoption of DM by microfluidic engineers has been slow, likely due to concerns over the resolution of the printers and the biocompatibility of the resins. We have developed microfluidic devices by SL in PEG-DA-based resins with automation and biocompatibility ratings similar to those made with PDMS. The resins allow for building transparent microchannels, microvalves, and multi-material devices containing hydrogels of larger-MW PEG-DA formulations.