Solvent-Mediated and Strain-Confined Annealing for Rapid, Green Fabrication of Mechanically Robust and Ionically Conductive Organohydrogels

Abstract

Ionic conductive organohydrogels combining freezing resistance, solvent retention and thermal stability are critical for flexible electronics and biointerfaces, yet their development is constrained by unsustainable fabrication and trade-offs among strength, toughness, and fatigue resistance. Here, we introduce a green, solvent-programmed strategy integrating phase separation and strain-confined annealing to construct anisotropic ionic conductive organohydrogels (ICOGs) with hierarchical architectures. Using a non-toxic glycerol−water co-solvent, this approach enables temperature-triggered gelation of poly(vinyl alcohol) into a bicontinuous network, while constrained annealing drives chain alignment, hydrogen-bond densification and crystallization to lock anisotropy. The resulting ICOGs exhibit mechanical synergy: tensile strength (21.83 MPa), toughness (23.24 MJ·m−3), fracture energy (38.89 kJ·m−2), and fatigue resistance (>20,000 cycles at 731 J·m−2). As strain sensors, they demonstrate linear electromechanical response (0−70% strain) and defect tolerance in notched specimens. This sustainable platform resolves the mechanics-processability conflict, offering a versatile pathway for wearable electronics, soft robotics and implantable bioelectronics.