Measurements of the bi-linear elasticity of identical carbon nanotubes

Measurements of the bi-linear elasticity of identical carbon nanotubes (CNTs) by both buckling process and electromechanical resonance are presented. When the bending moment is applied to a CNT, the elastic modulus of a CNT changes with its curvature on the bi-linear reaction, caused by the appearance of ripping mode, which is the wave like distortion or ripples on the inner arc of a bent CNT. In this paper we measure the elastic moduli of identical CNTs respectively by both buckling process using an atomic force microscope (AFM) cantilever E/sub b/ and electromechanical resonance E/sub e/ through nanorobotic manipulators inside a field emission scanning electron microscope (FE-SEM). Average of three samples shows that E/sub e/ (/spl sim/43 GPa) is much smaller than E/sub b/ (/spl sim/1.87 TPa). This is the first measurements of the bi-linear elasticity of the identical CNTs.