Stimuli-responsive hydrogel actuators for skin therapeutics and beyond

Stimuli-responsive hydrogels are innovative soft materials that have garnered significant attention in recent years. These hydrogels can undergo phase transitions or structural changes in response to external stimuli, offering considerable potential for use as actuators. They can effectively be used for drug delivery and disease treatment by responding flexibly to a variety of stimuli. This paper first categorizes the types of external stimuli that hydrogel actuators respond to and outlines their applications in skin therapeutics. It then reviews therapeutic potentials of hydrogel actuators beyond the skin, and discusses the challenges and future prospects for the development of stimuli-responsive hydrogel actuators.