Fabrication of microfluidic networks using a high power femtosecond fiber laser

Abstract

Photolithography is well established in the fabrication of microfluidic networks; however, it is difficult to fabricate designs which require multiple depths. Furthermore, the cost/time to produce photolithographic masks is problematic, particularly when prototyping. Here we describe fabrication of microfluidic branching networks with multi-depth structures, ranging from 10s to 100s of microns, using a femtosecond fiber laser with 10 W average power, followed by chemical etching in a 10:1 solution of 49% HF and 69% HNO₃. While this technique was originally developed using a nanosecond laser, this unique femtosecond laser enables greater processing precision and faster overall processing speed.