Design, Fabrication, and Characterization of Electrostatically Actuated Microcantilever Sensor for Temperature Detection

Microcantilever sensor technology is a next-generation electromechanical technique with broad application in chemical, physical, and biological detection. In this paper, we are using a microcantilever to detect the temperature. The sensing action essentially is the deflection of the microcantilever beam. In general, an optical detection method is used in microcantilever-based sensing techniques. However, in this paper, the direct electrical detection is used, which has an advantage of reduced complexity. The desired separation between the electrodes required is <;50 nm for temperature sensing application, which is too small to fabricate consistently. We proposed to use prestress voltage to achieve desired separation. This is explored through simulation and experimentation. The process to fabricate microcantilever-based sensor has been developed and the device has been fabricated with surface micromachining technology. To detect the different temperatures, a different level of electrostatic actuation voltage is needed for each temperature. The tuning can be done by adjusting the actuation voltage levels. Thus, this sensor can be described as tunable temperature sensor. The details of the operation of the device and electrical characterization are presented for temperature detection application in this paper. Transient measurements are also done to estimate the response time of sensor. The developed device can be utilized to protect the system from overheating and thereby failures in electronic circuit.