Abstract/Summary

In this report, we demonstrate the synthesis of photoresponsive polymeric hydrogel lattices using stereolithographic 3D printing to afford objects that can change shape when irradiated with UV-vis light. Methacrylate-based monomers featuring azobenzene units were used as the photo-actuator components. Co-polymerisation of these monomers with 2-hydroxyethyl methacrylate produced well-defined hydrogel lattices. Photo-actuation of the hydrogels led to contraction of the 3D printed lattices up to 23 % by volume. The ability of such photoresponsive hydrogel lattices to exhibit payload release has been studied using methylene blue as a drug mimic. Upon irradiation, the hydrogel lattice was squeezed like a sponge through photo-induced actuation in pulses, resulting in the controlled release of the pro-drug over 24 hours.