Elastic Deformation of Carbon-Nanotube Nanorings

A combined experimental theoretical study of the mechanical deformation of carbon-nanotube (CM) nanorings is presented. The CNT ring employed is formed by folding a long and thin single-walled-CNT bundle. The mechanical deformations of the CNT ring when it is pushed against and pulled away from a flat substrate are experimentally characterized in situ. inside a high-resolution scanning electron microscope through nanomanipulation. The experimental measurements clearly reveal that the CNT ring displays a purely elastic behavior during multiple repeated large-displacement deformation processes. A theoretical model based on nonlinear elastic:a theory is used to quantitatively study the mechanical behavior of the CNT ring and to interpret the experimental results. This work shows for the first tune that van der Waals interactions between the CNT ring and the substrate have significant effects on the ring's elastic deformation, including a bifurcation in its force displacement profile. The results suggest that CNT nanorings can be used as ultrasensitive force sensors and flexible and stretchable structural components in novel nanoscale mechanical and electromechanical systems.