Development of a novel carbon nanotube based printed and flexible pressure sensor

A flexible carbon nanotube (CNT) based capacitive pressure sensor was developed for the detection of varying applied pressures. The sensor was successfully fabricated using the screen printing technique. Polydimethylsiloxane (PDMS) was used as a dielectric layer and it was prepared using a PDMS pre-polymer and a curing agent mixed in a 10:1 ratio. The electrode was directly screen printed using conductive CNT ink onto the PDMS. The capability of the sensor to distinguish between varying applied pressures were investigated based on its capacitive response. It was observed that the CNT-based pressure sensor produced an 8.2% change in capacitance when compared to the base capacitance, for a maximum detectable pressure of 337 kPa. A 0.021% change in capacitance per kPa and a correlation coefficient of 0.9971 was also determined for the CNT-based pressure sensor. The capacitive response of the printed sensor demonstrated the feasibility of employing CNT-based electrodes for the development of efficient, flexible and cost-effective pressure sensors for sports, military, robotic, automotive and biomedical applications.