Rapid fabrication of microfluidic chip on PMMA substrate by CO ₂ laser

This paper presents a widely available CO ₂ laser scriber to perform the direct-writing ablation of poly(methyl methacrylate) (PMMA) substrate for the development of microfluidic chips. The surface quality of the ablated microchannels and the presence of debris and distortion were examined by scanning electron microscopy, atomic force microscopy and surface profile measurement techniques. The developed laser ablation system provides a versatile and economic approach for the fabrication of microfluidic chips on PMMA substrate. In the laser writing process, the desired microfluidic patterns are designed using commercial computer software and are then transferred to the laser scriber to ablate the trenches. The results show that a very smooth channel wall with surface roughness less than 4 nm can be achieved through the unfocusing fabrication method without any annealing process. The machining capability and versatility of the laser writing system are demonstrated through its application to the microfluidic chips fabrication on PMMA substrate.