SURFACE ROUGHNESS STUDY ON MICROCHANNELS OF CO₂ LASER FABRICATING PMMA-BASED MICROFLUIDIC CHIP

Abstract

A novel method named soak sacrificial layer ultrasonic method (SSLUM) has been presented for optimizing the surface roughness of the microchannels of polymethyl methacrylate (PMMA)-based microfluidic chips. CO 2 laser was used for ablative microchannels on the PMMA sheet, and the effects of key parameters including laser power, laser ablation speed and solution concentration on the surface roughness of microchannels were estimated and optimized by SSLUM. The experimental observation demonstrates that the surface roughness results mainly from the residues on the channel wall, which are produced by the bubbles movement and bursting. The research results show that the surface roughness can be improved effectively by using SSLUM. In our experiment, the best value was Ra [Formula: see text] 110[Formula: see text]nm with laser power 12[Formula: see text]W, laser ablation speed 10[Formula: see text]mm/s, the solution concentration 75%, and the time of ultrasonic vibration 25[Formula: see text]min. SSLUM is proven to be an effective, simple and rapid method for optimizing the surface roughness of microchannels of microfluidic chips.