Sequentially Coupled Thermal‐Ionic Modulation for Constructing Robust Muscle‐Like Hierarchical Hydrogels

ABSTRACT Emulating the multi‐scale hierarchical structures of muscles offers a promising approach for constructing mechanically robust hydrogels. However, engineering two structurally distinct architectures across micro‐to‐mesoscopic length scales via simple, sustainable, and widely applicable approaches remains challenging. Herein, we developed a sequentially coupled thermal‐ionic modulation strategy to fabricate robust muscle‐like hydrogel nanocomposites with mesoscale anisotropic and microscale hierarchical architectures simultaneously. The first‐tier mesoscale anisotropic hydrogel matrix was induced by controlled temperature gradient under thermally asymmetric cyclic freeze‐thaw process via a conductive/insulative design of gelation condition. The second‐tier microscale hierarchical architecture was further precisely generated by Hofmeister effect mediated ionic salting‐out treatment. This sequentially coupled thermal‐ionic modulation strategy, combined with nanoparticle‐assisted interfacial reinforcement, enables sustainable fabrication of robust muscle‐like hydrogel nanocomposite to achieve improved mechanical performance including 10.12 MPa ultimate strength, 512% failure strain, 23.24 MJ/m 3 toughness, 26.56 kJ/m 2 fracture energy, and 16.87 kJ/m 2 fatigue threshold. This work provides a practical route for constructing mechanically robust biomimetic materials with potential applications in load‐bearing biomaterials and fatigue‐resistant flexible electronics.