Stretchable, self-healing, conductive hydrogel fibers for strain sensing and triboelectric energy-harvesting smart textiles

Stretchable conductive fibers are essential for smart electronic textiles (E-textiles). Here, we develop a continuous dry-wet spinning approach to fabricate stretchable, conductive and self-healing hydrogel fibers. By tuning the contents of acrylamide (AAm) and N-acryloylglycinamide (NAGA), the physically cross-linked poly (NAGA-co-AAm) (PNA) hydrogel precursor exhibits thermally reversible sol-gel transition, which ensures the success of the spinning process. The obtained PNA hydrogel fiber achieves excellent tensile strength (2.27 Mpa), stretchability (900%), high conductivity (0.69 S m−1), and self-healing capability. With an elastomeric poly (methyl acrylate) (PMA) coating, the PNA/PMA core-sheath fiber shows excellent resistance to water evaporation and absorption. The strain sensing capability of the PNA/PMA fiber is demonstrated for monitoring human body motions. Furthermore, a triboelectric nanogenerator (TENG) textile woven from the PNA/PMA fibers is fabricated to convert mechanical motion energy into electric power. Our stretchable conductive hydrogel fibers suggest great potentials for next-generation multifunctional smart textiles and wearable electronics.