Vibration signature analysis of single walled carbon nanotube based nanomechanical sensors

In the present paper, the simulation of the mechanical responses of individual carbon nanotubes treated as thin shells with thickness has been done using FEM. The resonant frequencies of the fixed free and the bridged SWCNT have been investigated. This analysis explores the resonant frequency shift of SWCNTs caused by the changes in the size of CNT in terms of length as well as the masses. The results showed the sensitivity of the single walled carbon nanotubes to different masses and different lengths. The results indicate that the mass sensitivity of carbon nanotube nanobalances can reach 10(-21) g and the mass sensitivity increases when smaller size nanotube resonators are used in mass sensors. The vibration signature exhibits super-harmonic and sub-harmonic response with different level of mass. In order to explore the suitability of the SWCNT as a mass detector device, the simulation results of the resonant frequency of fixed free SWCNT are compared to the published experimental data. It is shown that the FEM simulation results are in good agreement with the experimental data and hence the current modelling approach is suitable as a coupled-field design tool for the development of SWCNT-based NEMS applications. (C) 2010 Elsevier B.V. All rights reserved.