Resolving strain in carbon nanotubes at the atomic level

Jamie H. Warner*, Neil P. Young, Angus I. Kirkland & G. Andrew D. Briggs.

Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom.


Nature Materials, 10,958962,(2011).


Details of how atomic structure responds to strain are essential for building a deeper picture of mechanics in nanomaterials. Here, we provide the first experimental evidence of atomic displacements associated with shear strain in single-walled carbon nanotubes (SWNTs) by direct imaging using aberration-corrected transmission electron microscopy. The atomic structure of a zig-zag SWNT is resolved with unprecedented accuracy and the strain induced by bending is mapped in two dimensions. We show the existence of a dominant non-uniform shear strain that varies along the SWNT axis. The direction of shear is opposite to what would be expected from a simple force applied perpendicular to the axis to produce the bending. This highlights the complex atomistic strain behaviour of beam-bending mechanics in highly anisotropic SWNTs.