Abstract

Rapid Micromolding of Sub-100 Micron Microfluidic Devices Using an 8K Resin 3D Printer

Amar Basu, Associate Professor, Wayne State University

Microfluidics relies on the ability to manufacture sub-100 micrometer fluidic channels. Conventional lithographic methods provide high resolution but have turnaround time of several days, while rapid prototyping methods (e.g., laser cutters, craft cutters, fused deposition modeling) have feature sizes of several hundred microns or more.  This talk describes a single-day process for fabricating sub-100 µm channels, leveraging a low-cost 8K digital light projection (DLP) 3D resin printer.  The process can create microchannels with 44 µm lateral resolution and 25 µm height, posts as small as 400 µm, aspect ratio up to 7, structures with varying z-height, integrated reservoirs for fluidic connections, and a built-in tray for casting.  This talk will cover the key process steps (mold printing, post-treatment, and casting polydimethylsiloxane (PDMS) elastomer)  and discusses strategies to obtain robust structures, prevent mold warpage, facilitate curing and removal of PDMS during molding, and recycle the solvents used in the process.  This process provides a balance between resolution, turnaround time, and cost (~USD 5 for a 2 × 5 × 0.5 cm3 chip) that may be useful for many microfluidics labs.