Multimodal Strain-Insensitive Liquid Metal Sheath–Core Fiber for Wearable Electronics

Highly conductive and strain-insensitive liquid metal fiber conductors are crucial for reliable signal transmission in wearable electronics. However, it is difficult to maintain high conductivity while ensuring stability under the multimodal strains of dynamic wearing conditions. Herein, using the prestretch-induced self-coiling mechanism, we developed a liquid metal core-sheath fiber with a built-in microhelix conductive pathway (H-LM fiber). Featuring an intrinsic continuous conductive pathway, the fiber exhibits a high initial conductivity of 7.21 × 10⁴ S/m and maintains a stable resistance with a change rate below 0.8% under various mechanical deformations, including stretching (120% strain), bending (<i>h</i>/<i>l</i>₀ = 2), pressing (5.05 N), and twisting (720°). Moreover, the H-LM fiber can be readily embroidered onto commercial garments, enabling reliable power delivery and sensing signal transmission under practical dynamic conditions, thereby offering a highly advantageous solution for digital garments.