Photoresponsive Hydrogel Microstructure Fabricated by Two‐Photon Initiated Polymerization

A photoresponsive polymeric hydrogel cantilever that deflects under illumination has been fabricated by using two‐photon three‐dimensional lithography. The hydrogel was prepared from a comonomer solution containing acryloylacetone, acrylamide, and N,N′‐methylene bisacrylamide. The photoresponse of the cantilever was activated by photoexcitation of acetylacetone groups at 244 nm. Deflection of the cantilever by ∼ 45° was effected upon UV irradiation for 20 min.