All‐Metal Flexible Fiber by Continuously Assembling Nanowires for High Electrical Conductivity

Abstract Fiber electronics booms as a new important field but is currently limited by the challenge of finding both highly flexible and conductive fiber electrodes. Here, all‐metal fibers based on nanowires are discovered. Silver nanowires are continuously assembled into robust fibers by salt‐induced aggregation and then firmly stabilized by plasmonic welding. The nanowire network structures provide them both high flexibility with moduli at the level of MPa and conductivities up to 10 6 S m −1 . They also show excellent electrochemical properties such as low impedance and high electrochemically active surface area. Their stable chronic single‐neuron recording is further demonstrated with good biocompatibility in vivo. These new fiber materials may provide more opportunities for the future development of fiber electronics.