MASS DETECTION USING SINGLE WALLED BORON NITRIDE NANOTUBE AS A NANOMECHANICAL RESONATOR
The feasibility of the Boron Nitride Nanotubes (BNNTs) as nanomechanical resonators, using continuum mechanics based approach and finite element method (FEM) is illustrated in this paper. Two types of end constraints of single walled boron nitride nanotubes (SWBNNTs), namely cantilevered and bridged are assumed. Analytical formulas based on continuum mechanics are used to examine the mass sensitivity of SWBNNTs considering as a thin wall tubes for both types of end constraints for different lengths and different diameters. The FEM analysis, considering SWBNNT as a transversely anisotropic material is performed and results are compared with the continuum mechanics based approach. The results indicated that the mass sensitivity of SWBNNT-based nanomechanical resonators can reach 10-8fg and a logarithmically linear relationship exists between the resonant frequency and the attached mass, when mass is larger than 10-7fg. The sensitivity of resonant frequency shift to both tube length and diameter has also been demonstrated. It is clear that the change in resonant frequency shift to tube length is more significant than that with the tube diameter and mass sensitivity increases when smaller size nanotube resonators are used in mass sensors. The simulation results based on present FEM found in good agreement with the analytical approach.