Research on reversible bonding of microfluidic chips based on stretch release adhesive strips

Abstract

The reversible bonding of microfluidic chips has been developing rapidly with the requirement of reusable microfluidic devices or the need to obtain the samples inside the chip. Traditional bonding methods for polymer‐based microfluidics, e.g., thermal bonding, permanently attach the substrate and cover plate. Sometimes, once the chip flow channel is blocked, it is difficult to clean and affect the reusability of the chip. This study proposes a new reversible bonding method for poly (methyl methacrylate) (PMMA) microfluidic chips with the help of stretch release adhesive strips. The designed microchannels were fabricated on the surface of PMMA plates using CO2 laser irradiation. Then, stretch release adhesive strips were used as an intermediate layer between the substrate (with microchannels) and another flat PMMA/PS/PC plate to seal the microchannel. The assembled chip sets were bonded at room temperature with bonding strength comparable with other permanent bonding methods. Experimental results show that simply pulling the adhesive layer by applying a shear force can easily detach the intermediate adhesive layer from both the substrate and cover plate to separate the bonded chipset. The proposed reversible bonding method is simple, rapid and has low residue and high bonding strength. Bacterial culture experiments were also conducted to verify the biocompatibility of the proposed bonding method. The proposed reversible bonding technique can be used for polymer‐based microfluidic devices that require sample recovery or chip reuse.Highlights The stretch release adhesive strip can provide high bond strength. It allows easy peeling for reversible bonding. It bonds at room temperature with simple operation. It has good transparency for easy observation of experiments. It has good biocompatibility.