Vibration Analysis of Defective Double Walled Carbon Nanotube Based Nano Resonators

Abstract

The dynamic analysis of zigzag and armchair double walled carbon nanotubes (DWCNTs) with different boundary condition has been performed using atomistic finite element method. The double walled carbon nanotube is modeled considering it as a space frame structure similar to a three dimensional beam. The elastic properties of beam element are calculated by considering mechanical characteristics of covalent bonds between the carbon atoms in the hexagonal lattice. Spring elements are used to describe the interlayer interactions between the inner and outer tubes caused due to the van der Waals forces. The mass of each beam element is assumed as point mass at nodes coinciding with carbon atoms at inner and outer wall of DWCNT. It has been reported that multiple atomic vacancies are formed during the manufacturing process in DWCNT which tend to migrate leading to a change in the mechanical characteristics. Simulations have been carried out to visualize the behaviour of such defective DWCNTs subjected to different boundary conditions. The results clearly state that the dynamic characteristics are greatly influence by defects like vacancies in it. Comparison with the other experimental and theoretical studies exhibits good association which suggests that defective DWCNTs can further be explored for mass sensing. This investigation is helpful in applications involving ultra-high frequency nano resonators which contain one or other type of manufacturing defects in it.