Variation in electrical resistance versus strain of an individual multiwalled carbon nanotube

Abstract

The electrical resistance of an individual multiwalled carbon nanotube (MWCNT) as a function of mechanical strain was investigated inside a scanning electron microscope. The mechanical strain was applied to the MWCNT by a tungsten tip controlled by a nanomanipulator. The contact resistance between an individual MWCNT and the tungsten tip decreased with the addition of carbon deposition during e-beam exposure. The electrical resistance was significantly changed during the elongation process of the MWCNT and corresponded with the nanotube strain. The resistance increased abruptly at the beginning of the tube fracture. The strain sensitivities of two individual MWCNT were calculated to be about 25.2 and 25.9, respectively. The unique characteristics in electrical resistance variation for different displacements of an individual MWCNT could be used in a strain gauge for strain sensing of nanomaterials or a micromechanical device for sensing force or pressure. CNTs are very strong and highly flexible and would be ideal for these applications.