Fabrication of Microfluidic Devices for Emulsion Formation by Microstereolithography

• Main Authors: Max J. Männel, Elif Baysak, Julian Thiele
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Molecules
• Subjects: projection micro-stereolithography; microfluidics; droplets; emulsions; three-dimensional; 3D printing
• Online Access: https://www.mdpi.com/1420-3049/26/9/2817

Droplet microfluidics—the art and science of forming droplets—has been revolutionary for high-throughput screening, directed evolution, single-cell sequencing, and material design. However, traditional fabrication techniques for microfluidic devices suffer from several disadvantages, including multistep processing, expensive facilities, and limited three-dimensional (3D) design flexibility. High-resolution additive manufacturing—and in particular, projection micro-stereolithography (PµSL)—provides a promising path for overcoming these drawbacks. Similar to polydimethylsiloxane-based microfluidics 20 years ago, 3D printing methods, such as PµSL, have provided a path toward a new era of microfluidic device design. PµSL greatly simplifies the device fabrication process, especially the access to truly 3D geometries, is cost-effective, and it enables multimaterial processing. In this review, we discuss both the basics and recent innovations in PµSL; the material basis with emphasis on custom-made photopolymer formulations; multimaterial 3D printing; and, 3D-printed microfluidic devices for emulsion formation as our focus application. Our goal is to support researchers in setting up their own PµSL system to fabricate tailor-made microfluidics.