Cation-Induced Assembly of Conductive MXene Fibers for Wearable Heater, Wireless Communication, and Stem Cell Differentiation

Emerging wearable electronics, wireless communication, and tissue engineering require the development of conductive fiber-shaped electrodes and biointerfaces. Ti 3 C 2 T x MXene nanosheets serve as promising building block units for the construction of highly conductive fibers with integrated functionalities, yet a facile and scalable fabrication scheme is highly required. Herein, a cation-induced assembly process is developed for the scalable fabrication of conductive fibers with MXene sheaths and alginate cores (abbreviated as [email protected] ). The fabrication scheme of [email protected] fibers includes the fast extrusion of alginate fibers followed by electrostatic assembly of MXene nanosheets, enabling high-speed fiber production. When multiple fabrication parameters are optimized, the [email protected] fibers exhibit a superior electrical conductivity of 1083 S cm –1, which can be integrated as Joule heaters into textiles for wearable thermal management. By triggering reversible de/hydration of alginate cores upon heating, the [email protected] fibers can be repeatedly contracted and generate large contraction stress that is >40 times higher than the ones of mammalian skeletal muscle. Furthermore, the [email protected] springs demonstrate large contraction strains up to 65.5% and are then fabricated into a reconfigurable dipole antenna to wirelessly monitor the surrounding heat sources. In the end, with the biocompatibility of MXene nanosheets, the [email protected] fibers enable the guidance of neural stem/progenitor cells differentiation and the promotion of neurite outgrowth. With a cation-induced assembly process, our multifunctional [email protected] fibers exhibit high scalability for future manufacturing and hold the prospect to inspire other applications.