An anisotropic multi-amine-mediated dynamic network for strong, tough, and self-strengthening conductive hydrogel

The conductive hydrogels have emerged as the promising bioelectronics in various applications. To address the persistent challenge of reconciling extreme mechanical robustness with outstanding electrical properties during the long-term use, we propose a synergistic strategy to develop a strong and highly conductive hydrogel with hierarchical network through sequential Dimethyl sulfoxide (DMSO) crystal-templating, solvent replacement, multi-amine-mediated crystal reorganization and co -polymerization. Taking the merits of the aligned microstructure, adaptive non-covalent interactions, and the re-organized Poly(vinyl alcohol) (PVA) crystalline domains, the resultant hydrogel could effectively dissipate the impact energy, demonstrating excellent tensile strength as high as 4.26 MPa with a satisfactory fracture strain of 206%. Besides, this reliable conductive hydrogel displays a tissue-like self-strengthening behavior upon cyclic mechanical training, where the respective tensile strength and strain could be further increased up to 8.5 MPa and 221%. Notably, the conductive particles could be firmly immobilized into the outer layer of hydrogel via in-situ co -polymerization between the multi-amine molecules (i.e., 2,4,6-Triaminopyrimidine) and aniline monomers. Due to the existence of anisotropic transport channels, the ductile hydrogel possesses high electrical conductivity up to 13 S⸱m −1 , and exhibits consistent sensitivity to external strains. The high-performances make the hydrogel as an efficient electronic device for real-time motion sensing.