LAUSR

In this paper, we mainly study the processing and manufacturing methods of the Koch fractal micromixer on polymethyl methacrylate (PMMA) substrate using a flexible and low-cost CO2 laser system. The structure of Koch fractal microchannel can increase the contact area of the fluids, prolong the mixing time and improve the mixing efficiency of the micromixer. The study focuses on the effect of the CO2 laser system processing power, scanning speed and the number of scanning times on the quality of microchannel. With the increase in processing power and the number of scanning times, the width and depth of the microchannel change more obviously; this contributes to the hot-bonding success of the Koch fractal micromixer, avoiding the hot-bonding failure causes by the overvoltage or overheat. At last, the CO2 laser output power of 7 W and a laser scanning speed of 10 mm/s combining a hot press bonding technique are chosen to fabricate a microfluidic chip within half an hour. The fabrication of microchannel on PMMA substrates with CO2 laser system will have a wide range of application values, resulting in lower costs and easier fabrication.