Mechanical fastening to enable room temperature packaging for LOCs based on biocompatible hydrogel thin film

This paper reports a microfabrication technique viable for the production of microfluidic devices which can be reusable through disassembly and re-assembly routines using mechanical fastening configuration. A biocompatible water swollen poly (hydroxyethyl methacrylate) (PHEMA) hydrogel thin film of thickness ranging from 200 to 1000 µm is incorporated in a thermoplastic based multilayer system, as such its effectiveness of sealing is investigated through liquid leakage tests. In the test, pressurized air is injected in liquid filled microchannels machined on the hard polymeric component and sealed on one side by a compressed PHEMA layer. The critical pressure values of the fluid corresponding to the leakage at the materials' interface have been registered for different hydrogel strain values and multiple microchannels depth. A COMSOL simulation has also been implemented to simulate the mechanical behaviour of the hydrogel in the custom device settings for different packaging and critical fluid flow pressure values.