Radial elasticity of single-walled carbon nanotube measured by atomic force microscopy

Effective radial modulus (E_radial) of straight single-walled carbon nanotubes (SWCNTs) grown directly on quartz substrate have been measured by using well-calibrated tapping mode and contact mode atomic force microscopies. It is found that the measured E_radial decreases from 57 to 9 GPa as the diameter of the SWCNTs increases from 0.92 to 1.91 nm. The current experimental results are consistent with the recently reported simulation data in both the data pattern and values. The method used in this research can also be applied to measure the mechanical properties of other low-dimension nanostructures, such as nanowires and nanodots.