5.4.5 A Hydrogen Sulfide Sensor Based on a Surface Acoustic Wave Resonator Combined with Ionic Liquid

Abstract

This paper describes a hydrogen sulfide (H 2 S) gas sensor using ionic liquid (IL).In this sensor, a reservoir for the IL was integrated above a surface acoustic wave (SAW) resonator.The IL serves as an absorber for H 2 S gas.Mass change due to this absorption is detected as a frequency-shift of the resonance.In this study, we fabricated and demonstrated the sensor using the LiNbO 3 SAW resonator with the resonant frequency of 38 MHz.The integrated reservoir was filled by the IL 1-butyl-3methlimidazlium tetrafluoroborate ([BMIM]-[BF 4 ]).As experimental results, we could observe the linear correlation between the amount of the frequency-shift and the exposure time of the sensor to the H 2 S gas.