A Highly-Sensitive Differential-Mode Microchemical Sensor Using TFBARs with On-Chip Microheater for Volatile Organic Compound (VOC) Detection

In this paper, we first report the microchemical sensor application of differential-mode Thin Film Bulk Acoustic Resonators (TFBARs) for Volatile Organic Compound (VOC) detection. Using the micro heater element, the membrane temperature of TFBARs can be increased up to 250 oC. Generally, VOCs are decomposed to CO and CO2at the temperature of above 200oC, the additional reference oscillator without VOC adsorption can be simply realized by heating the membrane. The RF signal mixer is used to determine the shift in oscillation frequency between sensing and reference oscillators. The frequency responses and sensitivities to benzene, ethanol, and formaldehyde are tested and presented, respectively.