Starch derivative/phytic acid-mediated hydrogen-bond reconstruction enables highly amorphous PVA hydrogels for tough,...

Wearable electronics require hydrogel-based sensors with high mechanical robustness, environmental stability, and multifunctionality. However, conventional poly(vinyl alcohol) (PVA) hydrogels often suffer from brittleness, dehydration, and freezing at low temperatures due to their highly crystalline hydrogen-bonded network. Herein, a bio-based hydrogen-bond reconstruction strategy was developed using carboxymethyl hydroxypropyl starch ether (CMHPS) and phytic acid (PA) to fabricate highly amorphous multifunctional PVA hydrogels. The abundant hydroxyl/carboxyl groups and flexible chains of CMHPS, together with the multiple phosphate groups of PA, effectively reconstructed the original PVA hydrogen-bond network, suppressed chain crystallization, and generated a dynamic crosslinked structure. Combined with a glycerol/water binary solvent system, the resulting hydrogel exhibited excellent anti-freezing and anti-drying properties. The optimized hydrogel achieved a tensile strength of 0.95 MPa, an elongation at break of 1173%, strong adhesion, efficient self-healing capability, and stable mechanical performance at -30 °C. Structural characterization and theoretical calculations confirmed enhanced intermolecular interactions and reduced PVA crystallinity. Furthermore, the hydrogel functioned as a flexible strain sensor for reliable human-motion monitoring. A self-powered sensing system based on a Zn/hydrogel/Cu configuration was also demonstrated, enabling strain-dependent voltage output and Morse-code signal transmission. This work demonstrates how renewable biomass-derived molecules can simultaneously improve hydrogel performance and functionality, providing a sustainable route toward next-generation self-powered wearable electronics.