Recyclable and Tough PVA‐Lignin Nanoparticle Eutectogel Fibers for Flexible Sensors under Harsh Environmental Conditions

ABSTRACT Conductive hydrogel fibers (CHFs) are emerging as promising building blocks for flexible sensors and human machine interaction (HMI), yet their practical deployment remains limited by poor environmental tolerance and recyclability, particularly under harsh outdoor conditions. Herein, we report a simple and scalable wet‐spinning strategy to fabricate recyclable and tough eutectogel fibers through a multi‐component synergistic design. By integrating poly(vinyl alcohol) (PVA) with lignin nanoparticles (LNPs) in a deep eutectic solvents (DESs) coagulation system, the resulting fibers exhibit high mechanical robustness (tensile strength up to 25 MPa), excellent stretchability, and stable ionic conductivity (0.241 S m − 1 ). Notably, the eutectogel fibers maintain reliable sensing performance at subzero temperatures (−20°C) and under intense ultraviolet irradiation, overcoming the intrinsic limitations of conventional aqueous hydrogel fibers. Owing to their toughness, environmental tolerance, and recyclability, these eutectogel fibers can be readily woven into textile‐based sensors for outdoor motion monitoring and advanced HMI applications.