Multi-functional performance of injectable ultra-stretchable nickel ion-mediated polyacrylic acid/DMSO hydrogels for flexible electronic sensor

Conductive hydrogel combining injectability, anti-freezing, adhesiveness, and ultra-stretchability is a promising candidate for flexible wearable electronic sensors. The key challenge lies in achieving a synergistic balance of multiple physical interactions through a simple strategy. Herein, we report a fully physically crosslinked conductive hydrogel composed of poly (acrylic acid) (PAA), dimethyl sulfoxide (DMSO), and Ni 2+ fabricated via a one-pot approach without chemical crosslinkers. Dynamic crosslinking arising from hydrogen-bonding networks and Ni 2+ -carboxylate coordination endows the hydrogel with robust mechanical properties (725 kPa tensile strength, 33,000 % elongation at break), efficient self-healing capability (∼90 % recovery), and excellent thermal stability down to −40 °C. The polar DMSO-rich environment and dynamic metal–ligand interactions synergistically enhance ionic conductivity and sensing sensitivity. Furthermore, the hydrogel exhibits high transparency, pH responsiveness, and interfacial adhesion, providing a multifunctional platform for high-performance flexible sensors.