Dual-Network Conductive Eutectogels with Enhanced Stretchability and Stability for Flexible Sensing

This study presents a dual-network composite gel synthesized from polyacrylamide (PAM), polysaccharides (sodium alginate/xanthan gum), and deep eutectic solvents (DES), demonstrating enhanced performance for flexible strain sensors. The composite gel incorporated a gallium-indium alloy (EGaIn) as a conductive filler to enable high stretchability, mechanical toughness, and superior electrical properties. The gel fabrication employed a solvent substitution strategy wherein water content was systematically replaced by DES, ensuring nonvolatility and structural stability. The resulting gel exhibited an impressive elongation at a break of 790%, tensile strength of 25 MPa, and strain sensitivity with a gauge factor (GF) of 3.62 at 150% strain, making it an ideal candidate for wearable strain sensors. The gel also demonstrated excellent resistance to freezing, high environmental stability, and minimal swelling in water. Furthermore, the gel showed rapid response and recovery times with excellent cyclic stability over 500 cycles. The multifunctional properties of the gel were further validated through its application in real-time human motion monitoring, handwriting recognition, and human-computer interactions, highlighting its potential for next-generation wearable sensor technologies. The developed eutectogels represent a promising solution for flexible, high-performance sensors with applications in health monitoring, wearable electronics, fire warning, and interactive systems.