Biomimetic Spinning of Strong and Hyperstable Eutectogel Fibers for Multifunctional Ionotronics

Stretchable eutectogel fibers hold exceptional promise for human physiological monitoring wearable electronics due to their nonvolatility, high ionic conductivity, and cost-effective fabrication. However, a significant challenge remains in achieving sufficient mechanical properties of eutectogel fibers for textile manufacturing and the ability to withstand long-term real-life usage, such as sweating and washing. Herein, hydrophobic eutectogel fibers (HEFs) with exceptional mechanical strength and environmental resilience were prepared via integrating prestretching and solvent evaporation-induced crystallization processes. The formation of abundant hydrogen bonds and the crystallization domain impart the HEFs with excellent tensile strength (5.5–22.5 MPa) and adjustable stretchability (75–375%). Most importantly, the HEF fibers keep remarkable stability (weight changes <2%) in aquatic environments under varying conditions of pH, humidity, detergent, and temperature. The HEF demonstrated multimodal sensing capabilities, including motion, weight, and temperature detection, with high-precision sensation (gauge factor = 2.2; temperature coefficient of resistance = 4.83 ± 0.2% K–1) and stability. These advancements set a foundation for smart wearable devices, marking a significant progress in the fields of eutectogel-based intelligent health monitoring.