Bioinspired Mineralized, Mechanically Reinforced Elastic Hydrogel without Hysteresis and Deformation-Rate Dependence

Living organisms exhibit exceptional mechanical adaptability under external stresses by integrating hierarchical inorganic-organic structures. Inspired by their biomineralization, this study presents a synthetic strategy to fabricate mechanically reinforced, hyperelastic, mineralized hydrogels via in situ silicification. Based on the natural bio-silicification process, we first mineralize silica nanoparticles from a nanocomplex containing high amounts of amine moieties in the hydrogel matrix. The size, shape, and distribution of silica nanoparticles were adjustable through the consecutive in situ process, which enables interlocking/entrapment of silica nanoparticles and polymer networks. The resulting silicified hydrogels overcome the conventional trade-off between strength/stiffness and toughness, thereby achieving the enhanced mechanical properties with hysteresis-free and deformation-rate-independent hyperelastic behaviors. Their superior mechanical characteristics allow the hydrogel to function as a strain sensor with exceptional durability under cyclic loading-unloading deformation. This strategy offers a versatile platform for the design of mechanically robust hydrogels.