High-Strength and High-Conductivity Core-Sheath Hydrogel Long Fibers for Stretchable Ionic Strain Sensors

Hydrogel fibers that can be raided possess considerable promise in the realm of flexible electronic gadgets, as they exhibit both exceptional durability and excellent conductivity. Using a continuous coaxial wet-spinning method, we have created a hydrogel long fiber with a core-sheath structure that is both strong, conductive, frost-resistant, and braidable. Hydroxymethylpropyl cellulose (HPMC) added lowconcentration polyvinyl alcohol (PVA) toform the core layer of the fiber he sheaths made of highconcentration PVA. Next, the fibers are submerged in a sodium chloride solution to create PVA@PVA-HPMC hydrogel fibers that exhibit remarkable tensile strength (6.7 MPa), extensive elongation (450%), excellent electrical conductivity (9.23 S/m), and exceptional resistance to freezing temperatures (below −20 °C). The hydrogel fibers are further encapsulated using PSPI copolymers to enhance their environmental stability. Finally, the PVA@PVA-HPMC fibers are applied as flexible sensors to detect human joint movements, and assembled into e-textiles to monitor the positional distribution of pressure.