Geometry-programmed self-wrinkling in organo-hydrogels for anisotropic mechanics and adaptive sensing.

Abstract

Gel-based soft materials are attractive for flexible electronics and biointerfaces but are often limited by insufficient mechanical robustness and constrained functional integration. Here, we introduce a geometry-programmed self-wrinkling strategy that enables the spontaneous formation of aligned wrinkle architectures during thermal-evaporative gelation of poly(vinyl alcohol)-based organo-hydrogels. Without external patterning or post-processing, this process produces materials with enhanced mechanical robustness and pronounced anisotropy in deformation, fracture, and ionic transport. By leveraging these intrinsic properties, we demonstrate multiple sensing and actuation functions, including directional strain sensing, multidirectional sliding detection, deformation-driven rolling sensors, and temperature-triggered alarms. These results highlight geometry-programmed self-wrinkling as a scalable route to integrate structural reinforcement and directional functionality into soft materials through a physically driven formation process.