Pico-watts thermal convective accelerometer based on CNT sensing element

This paper presents the design and characterization of a novel micro motion sensor using Carbon Nanotube (CNT) sensing element. This sensor is based on thermal convective sensing theory, and uses CNT bundles manipulated by dielec-trophoretic (DEP) forces to form the motion sensing element. The heat generation CNT bundle is first heated up in a micro chamber using constant current. External acceleration causes thermal convection within the chamber, which is detected by the fluctuation of the output voltage of the CNT sensing element working as a temperature sensor. The thermal sensing properties of CNT bundles are tested and analysed first. Then, the sensor´s responses to acceleration are monitored and reported. The effect of the driving current level is also investigated and reported. It is found that by using this detection method, the sensing block requires only tens of pico-watts to function as motion sensors.