Ultrastable cyclic bending response of carbon nanotube/copper laminate composite film

Abstract

Abstract Nanostructured metal thin films have high strength and high electrical conductivity, but their fatigue resistance is relative low due to the weak plasticity and ductility deformed by localization at grain boundary or interface. Here we report a carbon nanotube/copper laminate composite film with ultrahigh fatigue resistance, which exhibits history-independent cyclic bending response. The high dense wrinkling of composite film becomes the dominant cyclic deformation behavior. The cracks initiation and formation are voided by the wrinkling process releasing the bending stress. The residual stress and resistivity of composite film no longer increase even if the number of cycle reaches as high as105. This result provides us a novel insight to design nanoscale metal films with ultrahigh fatigue resistance and superior service ability.