Simulation of CNT based mass resonator sensor and investigation on the effect of vacancy defect on sensing performances

Abstract

In this paper carbon nanotube (CNT) as a mass resonator sensor has been modelled by molecular structural mechanics approach. Then the effect of a single vacancy defect and its position on the sensing performances has been simulated. The simulation shows that the natural frequency shift of the cantileverd CNT, is decreased by the vacancy defect. Besides, when the vacancy gets nearer to the tip of the cantilevered CNT, its effect reduces. Simulations show that the effect of single vacancy defect on bridged CNT, in one-fourth of its length, is equal to the cantilevered one. Choosing smaller CNTs with smaller aspect ratios leads to having sensors with higher sensitivities. Simulations show that there are some positions in cantilevered and bridged CNTs that the effect of vacancy in frequency shift is negligible and the bridged CNTs are less sensitive than cantilevered CNTs to defects.