A stretchable and conductive fiber for multifunctional sensing and energy harvesting

Fibers with high stretchability and conductivity are considered as essential building blocks for next-generation fiber-based electronics. Herein, we presented a facile, scalable, and environmentally-friendly approach for the fabrication of multifunctional fibers. The fiber obtained by wet-spinning technology is composed of MXene and carbon nanotube (CNT) embedded in polyurethane (PU), with a cobblestone-shaped gold nanostructure (namely, AuCNS) on its surface formed by spontaneous reduction between AuCl4¯ and MXene. The fiber exhibits high conductivity and excellent durability under mechanical deformations, which makes it promising for constructing wearable fiber-based devices. The formation of AuCNS significantly enhances the surface roughness and catalytic behavior of the fiber. An ultra-sensitive pressure sensor with high sensitivity, fast response time, and excellent durability was fabricated using the fiber as sensing units. Besides, a three-electrode fiber-based flexible electrochemical sensor for highly sensitive detection of H2O2 can be designed due to the excellent electrocatalytic activity of AuCNS. The fiber can also be used as an electrode for constructing a fiber-based triboelectric nanogenerator for water energy harvesting. All these indicate that this multifunctional fiber would hold great promise in next-generation fiber-based wearable sensors as well as self-powered systems.