Monolithic integration of carbon nanotubes based physical sensors

This study establishes a batch fabricated process to implement and monolithically integrate CNTs (carbon nanotubes) based physical sensors. In this process, vertically aligned CNTs (not horizontally aligned or mixed CNTs) are grown and patterned on Si-wafer as sensing elements, and also integrated with MEMS (microelectromechanical systems) structures. The mechanical deformation and temperature change is thus detected by the resistance change of such CNTs sensing elements. In applications, the CNTs-based pressure sensor and temperature sensor are monolithically fabricated on a chip. Preliminary measurements indicate the presented CNTs-based piezoresistive pressure sensor has a gauge factor of ~20, and the sensitivity of CNTs-based temperature sensor is 0.19/°C.