Ultrastrong MXene composite fibers through static-dynamic densification for wireless electronic textiles

Inherent transverse wrinkles and resulting voids between MXene (Ti₃C₂T_x) nanosheets hinder the preservation of their intrinsic mechanical and electrical properties in macroscopic fibers. Here, we demonstrate a controllable and continuous method for kilometer-scale fabrication of ultrastrong MXene composite fibers by utilizing static filling with short carbon nanotubes combined with dynamic thermal drawing using polylactic acid to bridge MXene nanosheets through hydrogen bonds. The resulting composite fibers achieve a record tensile strength of ~941.5 MPa and an electrical conductivity of ~3899.0 S cm^-1, with an even higher conductivity of ~12,836.4 S cm^-1 for the inner MXene fiber. This static-dynamic densification strategy significantly reduces voids with a low porosity of ~4.2% and enhances the nanosheet orientation factor to ~0.945. The embroidered smart textiles enable long-range, battery-free wireless health monitoring, body-coupled remote drone operation, and assisted communication with sustained mechanical durability. This versatile strategy offers a general pathway to fabricate high-performance functional fibers.