Two-Dimensional Strain Distribution Sensor Using Carbon Nanotubes

Abstract

A new highly sensitive strain measurement method has been developed by applying the change of the electronic conductivity of CNTs, which is caused by the distortion of the electronic band structure. A two-dimensional strain distribution sensor was developed by using thin-film processing. Finely area-arrayed multi-walled carbon nanotubes (MWCNTs) were grown on a silicon wafer by applying a chemical vapor deposition method, and the area-arrayed MWCNTs were interconnected by the lift-off process of titanium thin film. The height of the grown MWCNT was about 250 μm, and size of the bundle of the grown CNT was 40 μm square, and the pitch of the bundle was 1000 μm. Uni-axial pressure was applied to the sensor, and it was found that the gauge factor of the developed sensor was about 100. Thus, this sensor is usefull for detecting the two-dimensional distribution of compressive strain in micro-scale.,