Study aspect ratio of microchannel on different polymer substrates with CO2 laser and hot bonding for microfluidic chip

Abstract

The paper demonstrates four different polymer substrates including Polymethyl-methacrylate (PMMA), Polycarbonate (PC), Polystyene (PS) and Polyethylene Terephthalate (PET) for fabricating microfluidic chips using CO2 laser and hot bonding machine. The experimental methods are very simple and convenient. The work aims to obtain combination of optimal polymer for hot bonding through comparing the influence of different polymer cover plates on aspect ratio of different polymer microchannels at the same hot bonding parameters. There are three microchannels in each polymer substrate. And three microchannels are processed at three different laser parameters. The hot bonding parameters include bonding temperature of 95°C, pressure of 1Mpa for time of 9min. The results show PS cover plate with the basic plate of other substrates is the best due to stability of microfluidic chip and the ignored microchannel deformation. Next, a fluid mixing experiment in microfluidic chip with PMMA basic plate and PS cover plate is successfully performed. The microchannel in PMMA is processed with laser speed of 10mm/s, laser power of 12W, distance between the sheet surface and the lens of 7.5mm.