A triple-network hydrogel synergistically constructed via hydrophobic interactions, hemicellulose-mediated Diels-Alder bonds, and Fe3+ coordination for flexible sensors and TENGs

Polyacrylamide (PAM) -based conductive hydrogels show immense promise for flexible wearable sensors and triboelectric nanogenerators (TENGs). However, integrating superior mechanical properties, strong adhesion, high conductivity, and fatigue resistance within a single system remains a formidable challenge. Herein, a triple-network hydrogel is synergistically constructed via hydrophobic interactions, Diels-Alder dynamic covalent bonds, and Fe 3+ coordination. The hydrogel exhibits comprehensive performance: fracture stress of 1.42 MPa, strain of 718%, toughness of 4.94 MJ/m 3 , Young's modulus of 180.3 kPa, adhesion strength of 23.85 kPa to porcine skin, conductivity of 4.39 S/cm, and high sensitivity (gauge factor = 4.87, pressure sensitivity = 0.92 kPa −1 ). Benefiting from its rapid and stable signal response characteristics, this hydrogel holds significant potential for applications in human motion and subtle physiological signal monitoring. Moreover, the fabricated TENGs exhibit excellent energy harvesting capability. This work reports the design of multifunctional hydrogels featuring balanced mechanical, adhesive, and conductive properties to advance the development of flexible electronics and self-powered devices.