title: Highly twisted double-helix carbon nanotube yarns.
abstract: The strength and flexibility of carbon nanotubes (CNTs) allow them to be constructed into a variety of innovated architectures with fascinating properties. Here, we show that CNTs can be made into a highly twisted yarn-derived double-helix structure by a conventional twist-spinning process. The double-helix is a stable and hierarchical configuration consisting of two single-helical yarn segments, with controlled pitch and unique mechanical properties. While one of the yarn components breaks early under tension due to the highly twisted state, the second yarn produces much larger tensile strain and significantly prolongs the process until ultimate fracture. In addition, these elastic and conductive double-helix yarns show simultaneous and reversible resistance change in response to a wide range of input sources (mechanical, photo, and thermal) such as applied strains or stresses, light illumination, and environmental temperature. Our results indicate that it is possible to create higher-level, more complex architectures from CNT yarns and fabricate multifunctional nanomaterials with potential applications in many areas.
authors.affiliation: National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Centre for Composite Materials and Structures, Harbin Institute of Technology, Harbin 150080, P. R. China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Shang
authors.forename: Yibin
authors.initials: Y
authors.lastname: Li
authors.forename: Xiaodong
authors.initials: X
authors.lastname: He
authors.forename: Shanyi
authors.initials: S
authors.lastname: Du
authors.forename: Luhui
authors.initials: L
authors.lastname: Zhang
authors.forename: Enzheng
authors.initials: E
authors.lastname: Shi
authors.forename: Shiting
authors.initials: S
authors.lastname: Wu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Peixu
authors.initials: P
authors.lastname: Li
authors.forename: Jinquan
authors.initials: J
authors.lastname: Wei
authors.forename: Kunlin
authors.initials: K
authors.lastname: Wang
authors.forename: Hongwei
authors.initials: H
authors.lastname: Zhu
authors.forename: Dehai
authors.initials: D
authors.lastname: Wu
authors.forename: Anyuan
authors.initials: A
authors.lastname: Cao