Carbon Nanotubes: Super‐Stretchable Spring‐Like Carbon Nanotube Ropes (Adv. Mater. 21/2012)

Springy carbon nanotube ropes are made on page 2896 by Y. Li, A. Cao, and co-workers by twist-spinning single-walled nanotube films to form closely arranged loops with long-distance order. In contrast to previous straight yarns, these can be stretched along the axis to produce elongations with different elasticity. The nanotube ropes have spring constants comparable to conventional steel and can sustain very large tensile strains (up to 285%) without structural failure by loop separation and straightening.