Gas Sensing Using Static and Dynamic Modes Piezoresistive Microcantilever
A microcantilever has attracted interest in an application of high sensitivity sensor for chemical, physical, or biological objects. In this paper, we investigate a possibility of a piezoresistive microcantilever for gas sensing using a static and a dynamic modes operation. The gas used here is a liquefied petroleum gas (LPG). The measurement was performed by a Wheatstone bridge circuit in order to measure the microcantilever deflection or resonance frequency shift of the microcantilever vibration. The result shows that in the static mode, an output of Wheatstone bridge circuit, which attributes to the microcantilever deflection, changes due to the gas detection. For the dynamic mode, a voltage of peak-to-peak, which represents the microcantilever vibrations, decreases with increasing the gas flow time. This occurs due to the resonance frequency shift caused by the addition of gas molecules on the microcantilever surface. These results indicate that the developed system can be used as the gas sensor.