The microchannel of microfluidic chip fabrication by micro-powder blasting

The process of micro-powder blasting is the high speed gas flow which mixed the micro-particle and gas to impact the brittle substrate by the specialized nozzle. This paper combined various diameters Al2O3 eroding particle with a novel masking technique to fabricate the pattern channels in soda glass with a width to 2000 μm and depth down to 1631 μm. The masking technology for fabricating microchannel is consisted by the combination of two polymers: 1) the elastic and thermal-curable poly-(dimethyl siloxane) (PDMS) for its erosion resistance and 2) the brittle epoxy resin SU-8 for its photosensitivity. This paper discusses the processing procedure by the different processing parameters (micro-powder impact pressure, the distance between nozzle and substrate, micro-powder size, and micro-powder impact time) to find the optimal process. The results show that the micro-powder size is the most important factor for the depth of microchannel of microfluidic chip. The surface roughness of microchannel of microfluidic chip is nearly 5-6μm.