Axial vibration characteristics of carbon nanotube-based mass sensors containing nanoparticles using nonlocal elasticity theory

Abstract

Carbon nanotubes (CNTs) are sensitive elements for the fabrication of nanomechanical mass sensors with greatly improved sensitivity. In this paper, the axial vibration behavior of single-walled CNTs based mass sensors was examined by nonlocal elasticity theory and Euler–Bernoulli beam theory. The vibration governing equation of the system was derived by the Hamiltonian principle, and the relationships of frequency equations and responses describing the vibration characteristics were all established. An approximate analytical method and simple expression for calculating the fundamental frequency were provided to obtain the expressions of natural frequencies with explicit physical parameters. In addition, combining with the theoretical analysis and considering the damping environment of the sensor under actual working conditions, LAMMPS molecular dynamics simulations were applied to compare and discuss the influence of various physical factors on the vibration behaviors of mass sensors. And the stable vibration signal generated by the damping was used to identify whether the attached nanoparticles fall off. The data revealed that the increase in tip attached mass and adjustment nonlocal parameters could effectively improve the sensitivity of mass sensors.