Dual-functional thermal management textiles for dynamic temperature regulation based on ultra-stretchable spiral conductive composite yarn with 500%-strain thermal stability and durability.

Next-generation personal thermal management (PTM) textiles for daily routine environments are attracting extensive attention. However, challenges remain in developing multifunctional PTM textiles that are comfortable to wear, have motion stability and environmental adaptability. Herein, a novel design for fabricating a sandwich-structure PTM textile based on an ultra-stretchable spiral conductive composite yarn (SCCY) with strain-electric stability is proposed. An SCCY composed of carbon nanotubes (CNTs)/polyvinyl pyrrolidone (PVP)/waterborne polyurethane (WPU) and a drawn textured yarn (DTY) is fabricated through a dip-twisting and shaping process. The PVP not only facilitates the interfacial bonding between CNTs and yarn, but also constructs strong hydrogen bond interactions with WPU, resulting in improved structure stability and robust electrical performance. Benefitting from the optimized spiral and composite structure, the SCCY exhibits a fast thermal response (130 °C within 8 s), long-term durability (1500 cycles), and superior thermal stability under large deformation (Δ T/T 0 ≈ 8.4%, under 500%). By assembling a stretchable electrothermal fabric based on SCCYs with an elastic fabric and thermochromic layer, temperature visualization and dynamic temperature regulation are integrated into the textile. This multifunctional PTM textile not only features dual thermal regulation modes of radiant cooling and Joule heating, but also maintains flexibility, breathability, and excellent stretchability, which provides broad application prospects in next-generation wearable devices.