Double-Network PEDOT:PSS Xerogel Fibers with High Stretchability and Electrical Stability for Wearable Strain Sensing

Abstract

Conductive polymer xerogels provide a promising route toward mechanically stable and water-independent alternatives to conventional hydrogels for wearable bioelectronics. However, achieving high stretchability, mechanical robustness, and stable electrical performance in xerogel fibers remains challenging. Here, we develop highly stretchable and conductive double-network PEDOT:PSS xerogel fibers fabricated through freeze-thaw-induced physical crosslinking of poly vinyl alcohol (PVA) followed by borax-mediated crosslink formation. The resulting fibers exhibit enhanced network integrity and mechanical robustness, enabling tensile strength up to ~16 MPa and elongation at break exceeding 1100% at an optimized borax concentration, while maintaining stable electrical conductivity (~0.8 S m⁻¹). The fibers display reproducible straindependent resistance changes with gauge factors up to ~19 at high strain. When integrated as wearable sensors, the xerogel fibers enable reliable real-time monitoring of human motion, including finger, wrist, and elbow movements. This doublenetwork xerogel strategy provides a simple and scalable approach to engineering mechanically robust conductive fibers for next-generation wearable sensing and bioelectronic applications.