PVA eutectogel fibers reinforced with multiphysical networks for mechanically robust and wide-temperature flexible sensors

One-pot wet-spinning strategy for scalable fabrication of PVA eutectogel fibers with triple-network reinforcement. • Multiphysical networks synergistically integrate hydrogen bonds, ionic conduction, and crystalline domains for mechanical-electrical coupling. • Exceptional tensile strength (11 MPa) and elongation (1023%) overcoming strength-toughness trade-off. • Process-driven structure regulation paradigm shifting from composition optimization to forming control. Conductive hydrogels have been widely explored for intelligent wearable devices and flexible electronics; however, simultaneously achieving high mechanical robustness and wide-temperature stability remains challenging. Herein, a one-pot strategy is proposed to fabricate polyvinyl alcohol(PVA) eutectogel fibers using PVA as the polymer backbone, choline chloride and ethylene glycol as a green solvent system, and ionic liquids (ILs) as ion suppliers, thereby constructing a synergistically reinforced network composed of polymer network - ion-conducting network - crystalline reinforcing network. Assisted by uniaxial stretching and cyclic freezing–thawing treatments, the network structure becomes highly oriented and compact, leading to markedly enhanced mechanical properties and wide-temperature stability. The resulting PVA eutectogel fibers exhibit outstanding and tunable physical properties: specifically, the CEG/PVA₃ fibers possess a high tensile strength of 11 MPa and an ultrahigh elongation at break of 1023%, while the CEG/PVA₁ fibers achieve a peak electrical conductivity of 2.54 mS cm⁻¹ at 25 °C. Meanwhile, these fibers maintain stable strain-sensing performance over a broad temperature range from −40 to 60 °C with a rapid response time of approximately 0.2 s. This work presents a feasible strategy for developing mechanically robust, wide-temperature flexible sensors. Download: Download high-res image (198KB) Download: Download full-size image