Resonant frequency analysis of fixed-free single-walled carbon nanotube-based mass sensor

Carbon nanotubes (CNTs) have good mechanical properties and unique structural, electronic, thermal, and optical characteristics. Fixed-free single-walled carbon nanotubes (SWCNTs) have attracted intense interest in recent years due to their suitability for a wide range of applications, such as field emission and vacuum microelectronic devices, nano-sensors and nano-actuators, etc. This paper investigates the resonant frequency and mode shapes of a SWCNT analytically and via continuum mechanics-based finite element method (FEM) simulations using a beam-bending model. Additionally, this study explores the resonant frequency shift of the fixed-free SWCNT caused by the addition of a nano-scale particle to the beam tip in order to explore the suitability of the SWCNT as a mass detector device. The simulation results for the resonant frequency are compared to the theoretical solutions and published experimental data. It is shown that the FEM simulation results are in good agreement with the theoretical and experimental data and hence the current modeling approach is suitable as a coupled-field design tool for the development of SWCNT-based NEMS applications.