Micro‐ and Nanoprinting into Solids Using Reaction‐Diffusion Etching and Hydrogel Stamps

Micropatterned hydrogel stamps soaked in appropriate chemical etchants can imprint various types of micro- and nanoarchitectures into metals, conductive oxides, semiconductors, glasses, and crystals. Localized etching is mediated by a reaction-diffusion process initiated from the stamp microfeatures and gives lateral resolution down to approximately 300 nm. The method is well suited for the rapid prototyping of small-scale devices including multilevel microfluidic systems and curvilinear optical elements.