Frequency change by inter-walled length difference of double-wall carbon nanotube resonator

Ultrahigh frequency nanomechanical resonators based on double-walled carbon nanotubes with different wall lengths were investigated via classical molecular dynamics simulations. For a double-walled carbon nanotube resonator with a short outer wall, the free edge of the short outer wall plays an important role in the vibration of the long inner wall. For a double-walled carbon nanotube resonator with a short inner wall, the short inner wall can be considered as a flexible core, thus, the fundamental frequency is influenced by its length. By controlling the length of the inner or outer wall, various frequency devices can be realized by a single type of double-walled carbon nanotube with walls of equal length.