Strain-Insensitive Helical Conductive Fibers via Rotational Co-extrusion Wet Spinning for Motion-Adaptive Temperature Sensing

Abstract

The development of strain-insensitive conductive fibers (SICFs) is crucial for wearable electronics; however, existing methods often involve complex processes and lack scalability. Here, we propose a novel strategy integrating rotational co-extrusion with wet spinning to fabricate helical conductive fibers with exceptional strain insensitivity and temperature sensing capabilities. By dynamically controlling the nozzle rotation speed (0–100 r/min), we achieve programmable helical architectures in the conductive layer, which synergistically dissipate mechanical stress through geometric deformation and maintain conductive pathways via dynamic ion redistribution in porous structures. The resulting fibers exhibit ultra-low resistance variation (ΔR/R₀=3.81% at 100% strain) and outstanding stability under bending (90°), twisting (720°), and cyclic stretching (1000 cycles). Simultaneously, the embedded ionic liquid endows the fibers with high thermal sensitivity (71.78% resistance drop at 20–70 °C), enabling precise temperature monitoring even during motion. Notably, the fibers demonstrate a linear response in the physiologically critical 30–40 °C range (18.5% resistance change), outperforming existing SICFs in strain–temperature decoupling. This study not only innovatively proposes a scalable process that integrates helical structure programming, material compounding, and fiber forming into a single operation but also extends the application of rotational co-extrusion technology to the field of wet spinning. It provides novel insights for multifunctional conductive fibers in areas such as wearable health monitoring and soft robotics sensing.

Keywords

Rotational co-extrusion / Wet spinning process / Strain-insensitive fibers / Temperature sensing / Intelligent fiber

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Funding

Department of Science and Technology of Jilin Province(20250102131JC)

National Natural Science Foundation of China(52575332 U25A601)

RIGHTS & PERMISSIONS

Donghua University, Shanghai, China