Toward a practical CNT pressure sensor

Carbon nanotube (CNT) has numerous unique properties that may benefit creating new sensor technologies. CNT is intensely interested in sensing applications due to their exceptional mechanical strength, high Young’s modulus, and high current density. In this work, the design and simulation of a carbon nanotube on a circular substrate-based piezoresistive pressure sensor were studied. Single and multi-walled carbon nanotubes were utilized to evaluate the best sensitivity and time response. The effect of changing pressure on displacement, current density, and von Mises stress was investigated using a single carbon nanotube (CNT) and an array of CNTs. It was noticed that as the pressure increased, there was also an increase in displacement, current density, and von Mises stress. The sensitivity achieved by SWCNTs was 1.428 × 10−11 μAPa, while for MWCNTs, it was 7.5 × 10−12 μAPa and the rise time range was 0.18 to 0.1 s, while for the pressure tested range was from 50 to 150 kPa. Additionally, the influence of varying diameters on the resistance of SWCNT and MWCNTs was discussed. This design has established diameter limits ranging from 1 to 4 nm. It has been discovered that increasing the diameter results in a decrease in the energy bandgap from 0.426 to 0.10 eV and reduces resistance from 2143 to 543 kΩ at zero strain.