Carbon nanotube (CNT-) based continuous fiber, a CNT assembly that could potentially retain the superb properties of individual CNTs on a macroscopic scale, belongs to a fascinating new class of electronic materials with potential applications in electronics, sensing, and conducting wires.

Now,  researchers have reported, for the first time, the fabrication of CNT-fiber-based stretchable conductors by a simple prestraining-then-buckling approach. Upon release of the prestrain, the CNT fibers are readily kinked in-plane because of their high flexibility. This buckled shape is quite different from the sinusoidal shape observed previously in otherwise analogous systems.

Furthermore, the performance of the CNT fiber/PDMS composite film as a stretchable conductor has been tested under cyclic tensile loading. Very little variation in resistance (~1%) under multiple stretching-and-releasing cycles up to a prestrain level of 40% is observed, indicating the outstanding stability and repeatability in performance of CNT fiber/PDMS composite films as stretchable conductors. Together with their continuously improving mechanical performance, CNT fibers possessing the unique stretchability that has been demonstrated are expected to further improve their applicability as reinforcements for multifunctional composites.