The fabrication of polymer microfluidic devices using a solid-to-solid interfacial polyaddition

It is hard to permanently seal the microfluidic channels made of thermoset polymers without using conventional adhesives. Here, we reported a polyaddition-based mechanism to solve the problem. The method is based on introducing amine groups onto the surface of one material and epoxy groups on another material and enabling the amine-epoxide polyaddition reaction at their closely contacted solid-to-solid interface to establish a covalent and permanent bonding. It was successfully used to permanently seal polydimethylsiloxane (PDMS) microfluidic channels with glass in a scalable and multifunctional fashion and to seal epoxy (SU-8) microfluidic channels with PDMS. This type of interfacial polyaddition can be easily extended to other materials for microfluidic device fabrication and is expected to find some applications in specialty bonding.