Characterization of Soft Tooling Photopolymers and Processes for Micromixing Devices with Variable Cross-Section

Area of Science:

• Microfluidics
• Materials Science
• Additive Manufacturing

Background:

• Microfluidic devices are crucial for lab-on-a-chip applications.
• Fabrication of microfluidic devices often involves complex and costly methods.
• Polydimethylsiloxane (PDMS) is a common material for microfluidic devices due to its biocompatibility and flexibility.

Purpose of the Study:

• To characterize photopolymers and stereolithography processes for 3D-printed molds.
• To validate the soft tooling approach for fabricating microfluidic micromixing devices.
• To investigate the mixing performance of devices produced using this method.

Main Methods:

• Screening of various photopolymers and stereolithography techniques.
• Fabrication of 3D-printed molds for polydimethylsiloxane (PDMS) casting.
• Manufacturing and testing of an asymmetric split-and-recombine micromixer under varying flow regimes (Reynolds number 10-70).

Main Results:

• Successful production of 3D-printed molds and PDMS castings of micromixing devices.
• Achieved mixing efficiencies ranging from 3% to 96%, dependent on flow regime and device geometry (pitch-to-depth ratio).
• Demonstrated the capability to create devices with multiple cross-sections and varied layouts on a single mold.

Conclusions:

• 3D-printed soft tooling is a viable and effective method for fabricating microfluidic micromixing devices.
• The developed approach offers flexibility in device design, allowing for diverse cross-sections and layouts.
• This technique provides a cost-effective and adaptable solution for microfluidic device prototyping and production.