Highly stretchable electro-conductive yarn via wrapping carbon nanotube yarn on multifilament polyester yarn

By virtue of the light-weight, high conductivity, and extraordinary strength, carbon nanotube yarns (CNT yarn, CNTY) are attractive candidates for promoting wearable electronic textiles. However, the unstable conductivity of the CNTY due to piezoelectric characterization of the CNTs may severely affect the conductive performance of the CNTY that is woven into smart textiles. Herein, we report a highly stretchable and stable electro-conductive yarn fabricated by wrapping CNTY on the multifilament polyester yarn (MPY). The stretchable CNTY/MPY wrapping yarn exhibited not only significant-high tensile force (∼727.60 cN) but also ultra-high tensile strain (∼142.76%) compared to pristine CNTY (tensile force ∼211 cN, strain ∼20%). Furthermore, the CNTY/MPY wrapping yarn displayed very limited decrement (<0.5%) of resistance changes after cyclic loading and could still work even during ∼60% stretching. Moreover, this CNTY/MPY wrapping yarn presented steady-state temperature (205.5 °C) with a high quick electro-thermal response (with 1 s) when applied with 2 V voltage. In addition, the CNTY/MPY wrapping yarn could retain the electro-thermal stability when sewed into gloves, displaying low temperature-changes (<2%) under various deformations. Our work explored the potential applications of CNTY/MPY wrapping yarn for wearable smart textiles.