Tough, Transparent, and Multifunctional Eutectogels via Coordination‐Regulated Monomer Solubilization in Metal‐Salt Deep Eutectic Solvents

ABSTRACT Deep eutectic solvent (DES)‐based eutectogels are promising soft ionic materials for flexible electronics and wearable sensors, yet their development is fundamentally limited by poor monomer compatibility in conventional Type III choline chloride‐based DESs. Tertiary amine‐functionalized monomers, such as 2‐(dimethylamino)ethyl methacrylate (DMAEMA), exhibit low solubility in these hydrogen‐bond‐dominated systems due to polarity and interaction mismatches, which prevents uniform precursor formation and controllable polymerization. Here, we introduce a coordination‐regulated solvation strategy to overcome this intrinsic limitation. By polymerizing DMAEMA in a Type IV ZnCl 2– acetamide metal‐salt DES, Zn 2 + –amine pre‐coordination regulates the monomer solvation structure, enabling homogeneous dissolution and transparent gel formation. After polymerization, the retained zinc–amine coordination serves as dynamic sacrificial crosslinks that dissipate mechanical energy while preserving network integrity under large deformation. The resulting eutectogels achieve high tensile strength (2.07 MPa), extreme elongation (1957%), ultrahigh toughness (23.40 MJ m − 3 ), optical transparency (∼80%), autonomous self‐healing, and reliable strain‐ and pressure‐sensing responses. This work establishes coordination‐regulated solvation in metal salt‐based DESs as a general molecular design principle that bridges monomer processability and mechanical robustness in DES‐based polymer networks.