Dual Transduction Surface Acoustic Wave Gas Sensor for VOC Discrimination

A novel dual transduction surface acoustic wave (SAW) resonator gas sensor is proposed to enable single sensor gas identification. In contrast to conventional gas sensors, which only detect a single physical property of the sensing material, the proposed dual transduction sensor can simultaneously detect variations in both the mass and resistance of the sensing material. As a result, this single sensor can achieve gas identification by exploiting the unique relationship between the resistance and mass responses to the sensed gas. Reported experimental results show that the proposed sensor can identify volatile organic compounds, including ethanol, acetone, and tetrahydrofuran. The proposed dual transduction scheme can be readily applied to conventional SAW resonators, thereby enabling low-cost implementations through the use of existing SAW fabrication lines. In addition, it alleviates the need to fabricate large sensor arrays to discriminate between gases.