Secondary bonding of PMMA micromixer with high-pressure

This paper studies the process to fabricate a micromixer by bonding the PMMA sheets after CO2 laser processing microchannel. It has been widely used in analysis chemical and detection as its low cost. Chemical analysis chips are commonly produced using low-pressure bonding. The bonding strength of the micromixer is improved by secondary bonding with high-pressure, which can meet the requirements of the chemical analysis with higher flowing rate and higher pressure. The effects on the single-layer and multi-layer microchannels are compared with high-pressure and low-pressure bonding. The deformation of the width and height at low pressure and high pressure of the single-layer channel are 12.4 μm, 23.5 μm and 17.1 μm, 54.1 μm, respectively. The multi-layer channels are 43.44 μm, 23.7 μm and 78.1 μm, 27.7 μm. The influence on the height of the V-shaped microchannel is greater when the single-layer micromixer is performed with high-pressure bonding, and when multi-layer bonding with high-pressure, the effect on the width of the rectangular microchannel is obvious. In the process of secondary bonding and pressurization, the chip position can be appropriately adjusted to avoid deformation caused by uneven force on the chip during manual operation. Since high-pressure bonding has an effect on the shape of the microchannel, different bonding methods can be selected according to different requirements of the chemical analysis chips on microchannel quality and bonding strength.