MWCNT Based Thin Film Strain Sensor

In this study, the real time strain response of the Multiwalled Carbon Nanotube (MWCNT) film to different kinds of tensile loading and response of the MWCNT film to temperature changes at macroscale is studied experimentally. The strain is applied to the MWCNT film by attaching it to a brass specimen using vacuum bonding, and subjecting it to tensile loading. Voltage output from MWCNT film is obtained using four-point probe in conjunction with a sensitive voltage measurement device. Experimental results demonstrate a linear relationship between change in voltage across the film and change in strain in the brass specimen when subjected to tensile load. The observed electromechanical characteristics also exhibit excellent reversibility evident from the way the voltage of the MWCNT film recovers to its unstressed state upon unloading. The MWCNT film exhibited a stable and linear response to changes in temperature with the resistance observed to be decreasing as temperature is increased. The study of MWCNT response to changes in temperature was done over a limited range. The experimental results presented in this paper demonstrate the effectiveness of MWCNT thin film in strain sensing as well as highlight the effect of temperature on it.