Effect of CNTs and Interfacial Defects on the Vibration of CNT-Based Hybrid Nanotubes

Abstract

A hybrid nanotube (HNT) is fabricated by coating carbon nanotubes (CNTs) with a concentric coating layer. Vibration of the HNTs is of great interest due to its potential applications in nano-resonators, nanosensors/actuators and nanogenerators. In particular, it is expected that the super stiff but very light CNTs would largely up-shift the vibration frequency and improve the performance of the achieved nanodevices. On the other hand, the hybrid structures may lead to the defects at the CNT-coating layer interface, which would down-shift the frequency and impair the integrity of the HNT. This paper aims to examine these issues by using a multiple-beam model for the pristine HNTs and a finite element model for the defective ones. The frequencies are obtained for the first five modes of the HNTs reinforced by a single-wall or a multi-wall CNT. It was shown that the strengthening effect of the CNTs is substantial for the high frequency vibrations of the HNTs with a thin coating layer. In this case, the inverse effect of the interfacial defects can also be observed.