Grasping the little things: Modeling and simulation of the electromechanical behavior of individual carbon nanotubes and nanotweezers

Abstract

Nanotweezers are electromechanical nanosized devices with versatile applications. Due to the challenges for experiments on the nanoscale, the support of models and simulations is crucial to get a better insight into the operational mode of nanotweezers. In the current work, armchair and zigzag individual carbon nanotubes (CNTs) as well as nanotweezers are investigated with regard to their behavior under various prescribed electrostatic loads. The applied model is a combination of the model by Cox and Hill for the geometry, the modified molecular structural mechanics (MSM) model for the covalent bonds and the charge-dipole-model by Mayer for the electric field. Compared to the models based on the solution of the Schrdinger equation, the computational cost of the MSM model is much lower. A weak coupling is given between the mechanical and the electrical field through the application of the Coulomb forces on the mechanical model. The finite element software ABAQUS was used for the numerical simulation. It was shown that (i) the resulting strains and closing gaps are nearly identical for armchair and zigzag CNTs with the same diameter and that (ii) an increase in CNT length leads to greater strains for individual CNT and narrower closing gaps between the arms of the nanotweezers.

Keywords

• CNT
• Molecular structural mechanics
• Charge-dipole-model by Mayer
• Nanotweezer
• Finite element simulation