Characterization of 3D Stereolithography (SLA) Printed Polymer for Autonomous-Flow Microfluidic Devices

Abstract

3D Stereolithography (SLA) printing is a high-throughput, precise and reproducible manufacturing platform which makes it a desirable technique to develop microfluidic devices for bioanalytical applications. However, limited information exists regarding the physical, chemical, and biological properties of the polymer resins used in 3D SLA printing. This project demonstrates the characterization of a commercially available 3D SLA printed resin polymer used to develop an autonomous-flow (self-driven) microfluidic device. In this investigation, time-dependent materials characterization was done on the Formlabs clear V4 resin to observe changes in mechanical and surface properties. The clear, printed polymer was analyzed with attenuated total reflectance (ATR), tensile test, impact test, and scanning electron microscopy (SEM). Polymer biocompatibility was assessed with MTT cell cytotoxicity. Results from the surface characterization and mechanical testing demonstrated the polymer is a self-curing resin and its strength increased with time. These time-dependent mechanical and surface properties of the polymer along with its biocompatibility and cytotoxicity in cell culture informed the design of a microfluidic device capable of maintaining autonomous fluid flow. This study demonstrates the commercially available clear resin is capable of being used to design and develop autonomous-flow microfluidic devices for bioanalytical applications, however, improvements in “shelf-life” and optical clarity are necessary. Overall, this project contributes to the expanding movement towards integrating 3D SLA printing with high-throughput manufacture of microfluidic devices.