Static analysis of nano-electro-mechanical switches based on molecular dynamics simulation

The static characteristic of a micro-cantilever of carbon nanotube (CNT) in nano-electro-mechanical (NEM) switches was analyzed by molecular dynamics simulation. During simulation, the Tersoff-Brenner potential function was adopted to calculate C-C interactions and the L-J potential function was used to calculate C-Cu and Cu-Cu interactions. Methods of cut-off radius and neighbor lists were also used to improve the calculating speed. Both working states (ON and OFF) of the NEM switch were firstly simulated and the result shows that the closed voltage is 1.0 V. Then the bending characteristics of the CNT were simulated and the results indicate that the deformation of the CNT is in accordance with the classical elastic theory when the voltage is less than 1.0 V, it generates a Stone-Wales deformation when the voltage is in a rang of 1.0 and 1.9 V, a collapse structure or hole appears in the CNT when voltage was above 1.9 V, and the CNT is broken completely when voltage increases to 2.9 V. Finally, the acting force between atoms of the CNT was analyzed, the result shows the weakest binding is in the interface between the electrode and the CNT of the NEM switches. These results would provide a theory foundation of design and optimization of the nanostructure devices.