Enhanced sensing performance of superelastic thermally drawn liquid metal fibers through helical architecture while eliminating directional signal errors

Due to their potential use in creating advanced electronic textiles for wearable technology, functional fibers have garnered enormous interests. The presence of stretchable smart fibers has significantly expanded the application scenarios of intelligent fibers. However, preparing fibers that possess both excellent electrical performance and high stretchability remains a formidable challenge. The fabrication of stretchable multifunctional fiber-based sensors employing a scalable method is reported here. Using a thermal drawing process, the collaborative interplay between the hollow confined channels of superelastic poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) thermally drawn fibers and the high fluidity of liquid metal (LM) ensures the exceptional electrical performance of the fibers. Simultaneously, the presence of a helical structure further enhances both the sensing and mechanical properties. The helical two LM channel fiber-based sensors are capable of displaying more than 1000% strain, high stability over 1000 cycles, a quick pressure response and release time of 30.45 and 45.35 ms, and outstanding electrical conductivity of 8.075×105 S/m. In addition, the electrical conductivity of this fiber increases with strain level, reaching 3×106 S/m when the strain is 500%. Furthermore, due to their superior tension and compression sensing capabilities, flexible helical sensors offer considerable potential for use in wearable electronics applications such as human motion detection, Morse code compilation, multichannel sensing, and more.