Patterning polyacrylamide hydrogels by soft lithography

Because of the chemical flexibility and broad range of applications of hydrogels, the direct patterning of biocompatible gel structures certainly deserves to be fully explored. This paper describes a method of creating hydrogel patterns of poly(acrylamide) by soft lithography. Room-temperature moulding is employed in order to directly transfer microstructures into poly(acrylamide), in a parallel manner up to a resolution of 2 µm. During the imprinting process, the gel at the liquid state flows into the shape of the stamp, driven by a combination of spontaneous capillarity and pressure-induced transport, without using any photon-beam, solvent, and chemical surface treatment. After the polymerization of the system, a negative copy of the stamp pattern is therefore frozen on the target material surface.