Flexible and highly sensitive pressure sensor using multi-walled carbon nanotubes

Abstract

A flexible and highly sensitive pressure sensor using multiwalled carbon nanotube (MWCNT) was developed in order to assure safe and reliable operation of surgical assisting and care nursing robots. The investigation of the optimum growth condition for MWCNT was carried out to control the shape and size of the MWCNT. Electron beam evaporation (EB) method and arc plasma deposition (APD) method were used to deposit thin catalyst layers. Scanning probe microscope (SPM) was used to investigate the surface condition of the catalyst layers. In this investigation, it was made clear that depositing an iron catalyst layer of 5 nm was the best condition to fabricate MWCNT. In addition, a high quality MWCNT has been synthesized to develop a flexible and highly sensitive pressure sensor. In order to investigate the characteristics and sensitivity of the sensor, a loading test was carried out. It was found out, from this study, that the electrical resistance of the MWCNT sensor increased almost linearly with the applied load and the obtained gauge factor was about 70.