Fabrication of hydrogel microstructures using polymerization controlled by microcontact printing (PCmicroCP).

Hydrogels are widely applied as functional biomaterials in the diagnostic and therapeutic fields. For example, intelligent hydrogels containing ionic groups (pH responsive) and poly(ethylene glycol) have promising applications as pH responsive materials in the biomedical and pharmaceutical fields. For potential use of hydrogels in micro- and nano devices, methods are needed to fabricate structures of various geometries at the micro- and nano scale. In this work, polymerization controlled by microcontact printing (PCmicroCP) is utilized, which is a method that uses microcontact printing to spatially define polymerization zones. Specifically, gold surfaces were modified by a hydrophobic thiol self assembled monolayer via microcontact printing and then a hydrophilic prepolymer solution was applied and only spatially occupied the regions confined by the hydrophobic thiol. Subsequently, polymerization reactions were carried out to create hydrogel microstructures. The patterned hydrogel produced using these methods are highly uniform in size and shape, having potential application in the field of biomedical microdevices.