Post-Buckling Deformation of Single-Walled Carbon Nanotubes

We present a nanomechanical study of the post-buckling deformation of single-walled carbon nanotubes (SWNTs). One thin SWNT bundle is anchored as a clamped-hinged structure between a flexible atomic force microscopy (AFM) cantilever and a rigid manipulator probe by means of nanomanipulation inside a high resolution scanning electron microscope (SEM). Both the deformation curvatures of the clamped-hinged nanotube beam and the corresponding applied loads during the post-buckling deformation processes are concurrently measured, in situ, through recording the buckled nanotube beam shape and the deflection of the AFM cantilever, respectively, using the high resolution electron beam. Using our in-situ SEM nanomechanical testing platform, we perform tensile tests on the same nanotube structure to characterize its Young's modulus. Our experimental measurements of the post-buckling deformation curvatures of the bundled SWNTs and the corresponding applied loads are in reasonably good agreements with theoretical predictions based on a nonlinear elastica model. The results reported in this letter will be useful to the understanding of the structural deformation of one-dimensional nanostructures in the large displacement regime, and to the pursuit of their structural applications.