Atomistic Finite Element Modeling and Analysis of pinholes in Double Walled Carbon Nanotube based mass sensor

This paper deals with studying the mass sensing characteristics of defective Double Walled carbon Nanotubes (DWCNT) using atomistic finite element method. Simulations are performed on chiral, zigzag and armchair nanotubes with cantilever and bridged conditions using molecular structure mechanics approach. Carbon nanotubes are widely used in the design of nano sensors, nanoresonators and actuators. In this manuscript the authors have categorized defects like larger vacancies termed as pinhole into two types i.e. 6 missing atoms (A type) and 24(B Type) missing atoms on the outer wall of DWCNT. DWCNTs are modeled considering the weak van der waals force of attraction between the inner and outer tubes as a spring element (COMBIN14). The simulation results indicate that the resonant frequency of defective DWCNT reduces with the increase in chiral angle. The simulation results indicate fundamental frequency reduces with the increase in the number of pinhole defects in DWCNT. The maximum frequency reduction takes place when the defect is located nearer to the fixed end of DWCNT which signifies that position of the defect is an important parameter to judge the mass sensing characteristics of DWCNTs.