Large-scale production of highly stretchable CNT/Cotton/Spandex composite yarn for wearable applications

Incorporation of carbon nanotubes (CNTs) into textiles without sacrificing their intrinsic properties provides a promising platform in exploring wearable technology. However, manufacture of flexible, durable, and stretchable CNT/textile composites on an industrial scale is still a great challenge. We hereby report a facile way of incorporating CNTs into the traditional yarn manufacturing process by dipping and drying CNTs into cotton rovings followed by fabricating CNT/cotton/spandex composite yarn (CCSCY) in sirofil spinning. The existence of CNTs in CCSCY brings electrical conductivity to CCSCY while the mechanical properties and stretchability are preserved. We demonstrate that the CCSCY can be used as wearable strain sensors, exhibiting ultrahigh strain sensing range, excellent stability, and good washing durability. Furthermore, CCSCY can be used to accurately monitor the real-time human motions, such as leg bending, walking, finger bending, wrist activity, clenching fist, bending down, and pronouncing words. We also demonstrate that the CCSCY can be assembled into knitted fabrics as the conductors with electric heating performance. The reported manufacturing technology of CCSCY could lead to an industrial-scale development of e-textiles for wearable applications.