Rapidly Gelling, Highly Adhesive, and Mechanically Robust Ionogels for Stretchable and Wireless Electronics

Abstract Stretchable devices function at the biology/electrode interface, depending on the excellent conformality between electronic components and nonplanar surfaces. Various polymeric architecture‐based sensing platforms have been extensively explored for physiological signal readout, however, poor interfacial adhesion coupled with low mechanical characteristics lead to easy interfacial debonding. Herein, a novel adhesive capable of rapid gelation, strong adhesion, and high toughness, achieved through a polymerization‐induced phase‐separation strategy is reported. In this design, the cosolvent and polar polymer serve as amorphous and crystalline domains, respectively, with mechanical performances readily modulable by altering the formulation, ultimately reach toughness on par with elastomers. Remarkably, the adhesive undergoes a rapid sol–gel transition within several seconds, displaying strong adhesion, and high interfacial toughness on diverse substrates. Capitalizing on its enduring adhesion to wet tissues, a wearable electronic device capable of real‐time sweat monitoring during exercise is developed. To showcase its practical application, a portable and battery‐free sensing system is designed to further demonstrate various vertebral postures, aiding the regulation of physiological activities. This study not only pioneers the preparation of novel adhesives with excellent adhesion and high toughness but also paves the way for wearable devices in the era of Internet‐of‐Things.