Researchers develop a UV-programmable hydrogel actuator for bioinspired simulation

A joint team from National Taiwan University and Karlsruhe Institute of Technology has developed a novel hydrogel actuator whose movement can be programmed using UV light, enabling precise spatial control of thermoresponsive deformation for presenting a potential application in soft robotics and in vitro muscle models.

A recent study published in Small Structures introduces a photopatterned thermoresponsive hydrogel actuator made from poly(ethylene glycol)methylether acrylate and poly(N-isopropylacrylamide) (PPEGA–PNIPAM). This hydrogel can be selectively degraded by UV light, thereby locally tuning its thermoresponsive behavior and enabling spatial control over actuation.

The hydrogel actuator is fabricated via a UV photolithography method. Upon heating, only the non-degraded regions contract, creating programmed bending and motion patterns.

This novel strategy allows researchers to encode motion profiles into a single monolayer hydrogel, avoiding the need for complex multilayer structures or external stimuli beyond temperature.

Notably, this platform also incorporates gelatin methacrylate to enhance biocompatibility. In cell experiments, muscle precursor cells (C2C12) exhibited excellent viability and proliferation within the hydrogel matrix, demonstrating potential applications in tissue engineering and biomimetic muscle modeling.

Professor Shan-hui Hsu, Distinguished Professor at National Taiwan University and corresponding author, said, “This hydrogel system demonstrates how simple UV exposure can program complex actuation behavior. It offers a promising strategy for developing next-generation soft robotics, artificial muscles, and in vitro models with embedded logic.”