A Feedback Controlled Carbon Nanotube Based NEMS Device: Concept and Modeling

Abstract

A switchable carbon nanotube based nano-electromechanical systems (NEMS) device with close-loop feedback is examined. The device is made of a conductive multi-walled carbon nanotube (MWNT) placed as a cantilever over a micro-fabricated step. A bottom electrode, power supply and a resistor are also parts of the device circuit. The pull-in/pull-out and tunneling characteristics of the device are investigated by means of an electro-mechanical analysis. The model includes the concentration of electrical charge, at the end of the nanocantilever, and the van der Waals force. Finite kinematics accounting for large deformations of the cantilever is also included in the modeling. The result shows that the device has two well-defined stable equilibrium positions as a result of the tunneling and the incorporation of a feedback resistor to the circuit. The potential applications of the device include NEMS switches, random-access memory (RAM) elements, logic devices and electron-counters.