Decreasing Surface Roughness of Microchannels CO2 Laser Cut into Polystyrene (PS) to Produce Microfluidic Chips by Optimizing Operating Parameters
C-M. Hou, S-X. Wang, R-H. LV, Y-S. Huang, Z. Tian, Y-Z. Mu and X-Y. Chen
CO2 laser cutting is an advanced processing technology which can, with the assistance of computer-aided design (CAD) graphics, cut a variety of shapes on the surfaces of many polymer sheets. This work aims to analyse the effect of laser power, scanning speed, focal distance and number of cut passes on the surface roughness of polystyrene (PS) microchannels with CO2 laser cutting process. There are several experiments designed and the results were analysed by an orthogonal experimental method. Finally, optimal power, speed, focal distance and number of cut passes were obtained: laser power of 10 W; laser cutting speed of 8 mm/s; focal distance of 8 mm; and three cut passes, respectively. The experimental results show that the greatest influence factor is the number of cut passes. In the optimal case, the arithmetical mean roughness (Ra) can reach as little as 0.861 μm.
Keywords: CO2 laser, polystyrene (PS) sheet, microfluidic chip, microchannels, surface roughness, orthogonal test method, processing quality