Elastic strain of freely suspended single-wall carbon nanotube ropes

We have induced large elastic strains in ropes of single-wall carbon nanotubes, using an atomic force microscope in lateral force mode. Freely suspended ropes were observed to deform as elastic strings with tension proportional to elongation. Ropes were elastically deformed over >10 cycles without showing signs of plastic deformation. The maximum strain observed, $5.8±0.9%,$ gives a lower bound of $45±7 GPa$ for the tensile strength (specifically, yield stress) of single-wall nanotube ropes.