Rapid prototyping of PMMA microfluidic chips utilizing a CO2 laser

A commercially available CO 2 laser scriber is used to perform the direct-writing ablation of polymethyl-methacrylate (PMMA) substrates for microfluidic applications. The microfluidic designs are created using commercial layout software and are converted into the command signals required to drive the laser scriber in such a way as to reproduce the desired microchannel configuration on the surface of a PMMA substrate. The aspect ratio and surface quality of the ablated microchannels are examined using scanning electron microscopy and atomic force microscopy surface measurement techniques. The results show that a smooth channel wall can be obtained without the need for a post-machining annealing operation by performing the scribing process with the CO 2 laser beam in an unfocused condition. The practicality of the proposed approach is demonstrated by fabricating two microfluidic chips, namely a cytometer, and an integrating microfluidic chip for methanol detection, respectively. The results confirm that the proposed unfocused ablation technique represents a viable solution for the rapid and economic fabrication of a wide variety of PMMA-based microfluidic chips.