Dynamic Hydrogen Bond‐Synergized Conductive Hydrogel With High Tensility and Strong Adhesion: Flexible Sensor Applications From Human Motion Monitoring to Handwriting Recognition

Conductive hydrogels have emerged as a research hotspot in the field of flexible sensing. However, existing materials commonly suffer from insufficient adhesion and limited sensitivity. In this study, a novel polyacrylic acid (PAA)‐based composite conductive hydrogel (PHCP) was prepared. Hydroxypropyl methylcellulose, chitosan, and conductive polydopamine‐modified polypyrrole composite particles were incorporated into the PAA hydrogel matrix to obtain a stable multidimensional crosslinked network through the synergistic effects of dynamic hydrogen‐bonding and electrostatic interactions. The resulting PHCP hydrogel exhibits outstanding performance, with a fracture strain of up to 1205.5%, a tensile strength of 129.7 kPa, and a maximum adhesion strength of 21.6 kPa on substrates such as wood. The sensor demonstrates a gauge factor of 2.63 in the 150%–400% strain range and a sensitivity of 2.16 kPa −1 in the 0–10 kPa pressure range, with both response and recovery times being as short as 0.33 s. Notably, it endures 150 stretching cycles without fracture. In practical applications, the hydrogel can stably monitor joint movements of fingers, wrists, and elbows; accurately distinguish motion signals; and recognize handwritten characters such as “A,” “T,” “C,” and “OK.” Through a synergistic multicomponent design, this study addresses the challenge of simultaneously achieving mechanical stability and high sensitivity in flexible sensors, offering a novel material solution for electronic skin, wearable devices, and human–machine interaction applications.