Strain-Enhanced Electromagnetic Interference Shielding Enabled by Rigid–Flexible Bridging Networks in Coaxial Fibers

Abstract Electrically conductive and highly elastic fibers serve as essential building blocks for smart fabrics and wearable electronics. Nevertheless, conventional conductive fibers tend to exhibit pronounced strain sensitivity, which results in substantial degradation of their electromagnetic interference (EMI) shielding performance under deformation. Here, a coaxial wet-spinning technique was employed to fabricate an ST@MPLM fiber. The fiber featured a silica (SiO2)/thermoplastic polyurethane (TPU) sheath (ST) and an MXene-permeating-liquid metal (MPLM) core, containing a rigid–flexible bridging dynamic conductive network. The resulting fiber exhibited large-strain tolerance, achieving a maximum strain of 632.8%. The corresponding fabric retained 102.4% of its EMI shielding effectiveness (SE) at 200% strain, demonstrating strain-enhanced EMI shielding behavior. The hydrogen bonds between TPU and LM, together with the Ti–O → Ga3+ coordination bonds at the MXene–LM droplet interfaces, facilitate the dynamic reconstruction and bridging of the conductive network during stretching. Furthermore, the fabric integrated Joule heating, infrared stealth, and dynamic visual camouflage capabilities, highlighting its potential in smart wearables and multispectral protection.