Defect Engineering-Induced Creep-Free Hyperelastic Gels.

Viscoelastic creep in elastomer originates fundamentally from the molecular-scale slippage and disentanglement of polymer chains governed by weak intermolecular interactions and imperfect crosslinking. Consequently, residual strain generated by long-term mechanical loading severely limits the mechanical stability of gel materials. In this study, we proposed a sub-unit-cell-scale defect engineering induced toughening strategy for fabricating creep-free hyperelastic hydrogels. Within the nanospaces created by linker and cluster defects in metal-organic frameworks (MOFs), strong confined interaction between in situ polymerized polymers and MOF crystals enables rapid self-reinforcement and remarkable creep resistance. The as-prepared hydrogels exhibited low hysteresis with full recovery under 99% compressive strain, negligible creep, and outstanding fatigue resistance over 25 000 loading cycles. These features render our hydrogels a promising candidate for drift-free iontronic sensors, allowing long-term stable monitoring in air, underwater, and other complex environments.