Rapid prototyping of multiphase microfluidics with robotic cutters

Abstract

Microfluidic devices offer novel techniques to address biological and biomedical issues. Standard microfluidic fabrication uses photolithography to pattern channels on silicon wafers with high resolution. Even the relatively straightforward SU8 and soft lithography in microfluidics require investing and training in photolithography, which is also time consuming due to complicated thick resist procedures, including sensitive substrate pretreatment, coating, soft bake, expose, post-exposure bake, and developing steps. However, for applications where low resolution (>200 μm) and high turn-around (> 4 designs/day) prototyping are met with little or no lithography infrastructure, robotic cutters [1] offer flexible options for making glass and PDMS microfluidics. We describe the use of robotics cutters for designing microfluidic geometries, and compliment it with safe glass etching, with depths down to 60 μm. Soft lithography patterning of 200 μm thick PDMS membrane was also explored. Without high equipment investment and lengthy student training, both glass and PDMS microfluidics can be achieved in small facilities using this technique.