Strong MXene Induced Conductive Silk Fibers

Conductive silk fibers (CSFs) are attractive in the field of flexible wearable electronics and textiles, but it still exists a great challenge to simultaneously enhance the electrical conductivity and mechanical properties. Inspired by the core-sheath structure of Bombyx mori silks, a continuous strategy is demonstrated for the fabrication the strong MXene induced conductive silk fibers (MCSFs). The sericin sheath of silk fibers (SFs) is replaced by MXene/sodium alginate (MSA) layer, and the ultrathin sheath layer is tightly bridged with the core through strong interfacial interactions, including hydrogen bonds and electrostatic interactions. Therefore, the MCSFs show extraordinary tensile strength of 1037.9 MPa and outstanding electrical conductivity of 6400 S m^-1, which exhibits obvious advantages compared with the previous reported silk fibers modified by other methods. In addition, the MCSFs also have a high toughness of 194.9 MJ m^-3 and an ultra-sensitive gauge factor of 2269.3, resulting in their ability to monitor human pulse, body movements, and changes of ambient humidity in real time. The proposed bioinspired strategy for continuously fabricating ultra-strong and tough MCSFs provides an avenue for implementing functionalized silk fibers in next-generation wearable technologies, intelligent textiles, and human-machine interaction etc.