Ion–Electron Dual-Conductive High-Performance PVA-Based Conductive Hydrogel for Wearable Strain Sensors

Current research on conductive hydrogels for flexible wearable sensors has attracted significant attention, yet their practical applications face limitations. The balancing of mechanical properties and electrical conductivity remains the central obstacle─existing hydrogels cannot simultaneously achieve high strength, high conductivity, and rapid response. Herein, we fabricate a poly(vinyl alcohol) (PVA)-based conductive hydrogel with an ionic-electronic dual-conduction network through a method combining dehydration-induced densification with synergistic crystallization and salting-out aggregation followed by rehydration. This hydrogel exhibits exceptional mechanical properties: tensile strength of 34.216 MPa, fracture strain of 402%, elastic modulus of 16.18 MPa, and toughness of 76.77 MJ m–3. Simultaneously, it demonstrated high electrical conductivity (3.7514 S/m). As a strain sensor, the hydrogel achieves three-stage high sensitivity (GF = 3.08–4.12), millisecond-level response (198 ms), and 500 cycle stability. It successfully monitors multijoint human motions (neck, elbow, knee, etc.), generating real-time signals synchronized with physiological deformations. This study presents a significant advance in mitigating the long-standing trade-off between mechanical robustness and electrical performance in conductive hydrogels through a rational ion–polymer interaction design.