The effect of pinhole defect on vibrational characteristics of single walled carbon nanotube

Carbon nanotubes are widely used in the design of nano sensors and actuators. Any defect in the manufactured nanotube affects its sensing performance and also influences its dynamic behavior. In this paper, the effect of pinhole defects on the dynamic characteristics of carbon nanotubes is investigated using continuum mechanics and the molecular structural mechanics approach. Dynamic analysis is performed for achiral nanotubes using the continuum mechanics approach with cantilever boundary condition, while for chiral nanotubes the molecular structural mechanics method is used. The shift of the principal frequency of the nanotube with number of pinhole defects on the length is observed and analyzed. The simulation results indicate that the existence of defects mostly affects the resonant frequency (bending rigidity) of single walled carbon nanotubes as the number of defects (pinhole) increase. Further, it is also observed that with the reduction in tube length, the variations in resonant frequency are enhanced. However, it is found that the frequency variation is less sensitive to the nanotube diameter.

Research highlights
► Dynamic analysis of achiral and chiral nanotubes with pinhole defect is performed.
► Shift of the principal frequency of the nanotube with number of pinhole defects is analyzed.
► Existence of multiple defects affects the resonant frequency of carbon nanotubes.
► Reduction in nanotube length enhances the variations in resonant frequency.
► Frequency variation is less sensitive to the nanotube diameter.