Ion-Conductive Elastomers with Enhanced Mechanical Performance and Electrical Conductivity via a Nano-Synergistic Transport Mechanism

Abstract Flexible ion-conductive elastomers have emerged as promising materials for wearable humidity sensors owing to their excellent stretchability and efficient ion transport capability. However, simultaneously achieving high ionic conductivity and excellent mechanical performance remains a significant challenge, primarily because the incorporation of high loadings of ionic components often induces solvation effects within polymer networks and compromises their mechanical stability. To address this challenge, we developed an ion-conductive elastomer with enhanced mechanical robustness and efficient ion transport capability by constructing a hydrogen-bond-anchored micro/nanostructured conductive network. Specifically, amino-functionalized SiO2 serves not only as a nanoreinforcing phase but also as a “bridging node” for ion transport through multiple hydrogen-bond anchoring interactions with polyurethane chains, enabling the formation of a continuous micro/nanoscale ionic conductive network while preserving the structural stability of the polymer matrix. The resulting ion-conductive elastomer exhibits high ionic conductivity (1.4 × 10–2 S/m), high tensile strength (2.17 MPa), and recyclability, achieving an effective synergy between mechanical performance and ion transport properties. Based on a humidity-induced ion transport mechanism, the fabricated flexible humidity sensor demonstrates rapid, stable, and reversible responses over a broad relative humidity range. This work provides a new material design strategy for developing high-performance, sustainable, and flexible ion-conductive polyurethane-based wearable humidity sensors.