Self‐Healing and Ultra‐Stretchable Hydrogel Strain Sensor Based on Poly (AAm‐co‐AMPS) for Multifunctional Biomedical Applications

Abstract The next generation of wearable biomedical devices demands materials that behave like soft skin, stretchable, self‐healing, and capable of continuous, high‐fidelity sensing. Conductive hydrogels embody this vision, merging electronic function with biological compatibility. However, low cost, high elasticity with prompt self‐healing capabilities and real‐time sensing within single hydrogel systems remain challenging. Here, a soft highly stretchable, UV‐curable hydrogel system engineered from polyvinyl alcohol (PVA), 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS), acrylamide (AM), N,N′‐methylenebisacrylamide (MBA), and photo‐initiator, 2‐hydroxy‐4‐(2‐hydroxyethoxy)‐2‐methylpropiophenone (Irgacure 2959) is reported. The synthesized hydrogel exhibits exceptional mechanical and functional performance, including ultra‐high stretchability up to 1000%, autonomous self‐healing within 3 s, and mechanical stability over 1000 cycles at 20% strain. It also delivers a rapid electromechanical response, with a response time of 414 ms and recovery time of 460 ms, enabling real‐time monitoring of joint and muscle motion. Furthermore, the sensor delivered reliable and repeatable signal outputs when integrated onto divers’ anatomical sites, including the finger and wrist, effectively capturing complex motion dynamics. Overall, this study presents a scalable, low‐cost, and environmentally friendly fabrication route for hydrogel‐based sensors, advancing the way for next‐generation wearable healthcare technologies.