A Pressure‐Tolerant Composite Hydrogel for Wide‐Range, High‐Sensitivity Dual‐Mode Piezoresistive‐Piezoionic Pressure Sensing

Single‐mechanism hydrogel sensors struggle to simultaneously recognize static/dynamic pressure, map spatial patterns, and decode complex signals, while integrating dual‐mode (e.g., piezoresistive/piezoionic) sensing, mechanical robustness, and environmental resilience remains challenging. Herein, we develop a multifunctional interpenetrating polymer network hydrogel, p(AM‐co‐AA)/chitosan (CS), reinforced with lignin nanoparticles and a ternary supramolecular ionic liquid. Fabricated at room temperature via redox‐initiated polymerization and dynamic imine crosslinking, the hydrogel features synergistic hydrogen bonding and metal‐ligand coordination. This architecture delivers 14.8 MPa compressive strength, autonomous self‐healing (<8 h), strong adhesion (249.3 kPa), anti‐freezing stability (−65°C), excellent moisture retention, high compressive sensitivity ( S max = 19.91 kPa − 1 ), an ultrabroad pressure detection range (100 Pa to 10 MPa), and a pronounced piezoionic response. The sensor enables real‐time handwriting recognition, secure Morse code transmission, and high‐resolution spatial mapping via flexible arrays. This scalable strategy advances robust hydrogel e‐skins for complex mechanical signal perception across diverse environments.