Dynamic Interchain Regulated Responsive Hydrogels With Stable Adhesion and On‐Demand Detachment for Comfortable Wearable Sensors

ABSTRACT With the rapid advancement of wearable electronics and the Internet of Things, hydrogels have emerged as promising candidates for human motion monitoring. However, existing hydrogel sensors generally suffer from critical issues such as poor adhesive stability, susceptibility to signal distortion, insufficient biocompatibility, and challenges in on‐demand detachment under sweating conditions, which severely limit their practical applications. Herein, this study reports a novel PASLC hydrogel (P(AAc‐co‐SBMA‐co‐LMA)/CMC) engineered to address these challenges. Through the synergy of electrostatic shielding and salting‐out effects, the hydrogel dynamically regulates the intermolecular interactions, achieving the dual functions of stable adhesion in sweating environments and on‐demand detachment in pure water. Specifically, the hydrogel leverages sodium ions from sweat to shield the electrostatic repulsion between carboxyl groups and enhance interchain cohesion. Concurrently, it weakens the hydrogel‐water interaction via the salting‐out effect, maintaining a low swelling ratio and structural integrity in salt‐containing environments. Consequently, the wet adhesion strength remains above 101.8 kPa, and the hydrogel exhibits high sensing sensitivity (maximum GF = 4.7) and low hysteresis, enabling stable capture of motion signals even during strenuous exercise involving profuse sweating. Conversely, in pure water, the hydrogel swells rapidly and drops drastically to 15.7 kPa, facilitating painless detachment. Additionally, the PASLC hydrogel possesses excellent biocompatibility. When integrated with a Bluetooth wireless sensing system, it enables real‐time, multi‐channel monitoring of complex human multi‐joint movements. This innovative design provides new insights for the development of sweat‐adaptable adhesive materials, significantly broadening the application scenarios of hydrogels in next‐generation wearable sensors.