In situ Laser-assisted Micrnmachining of Environmentally-responsive Hydrogel Films

Traditional micromachining techniques, such as lithography, etching, and micro-molding, to pattern hydrogel thin films, are time consuming, expensive, and do not scale well to large production. In this paper, we demonstrate a direct laser patterning of environmental responsive hydrogel films, allowing low cost, fast, and scalable fabrication for in situ mass production. We characterized and analyzed a series of transient features of the laser-engineered hydrogel, including the ablated width, sidewall quality, and resolution as a function of laser beam parameters and hydrogel thermal properties at different hydration states (from wet to fully dried). The optimal feature quality is achieved in hydrogels dried for 1-2 hours (40-60% weight loss), thus identifying a temporal window for a rapid end-to-end fabrication.