Surface acoustic wave based sensors employing ionic liquid for hydrogen sulfide gas detection

• Published in: Microsystem technologies : sensors, actuators, systems integration actuators, systems integration, 2013-08, Vol.19 (8), p.1255-1259
• Main Authors: Murakawa, Yoshinobu, Hara, Motoaki, Oguchi, Hiroyuki, Hamate, Yuichiro, Kuwano, Hiroki
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Electronics and Microelectronics; Engineering; Exact sciences and technology; Instrumentation; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical Engineering; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Nanotechnology; Physics; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Technical Paper
• ISSN: 0946-7076; 1432-1858
• DOI: 10.1007/s00542-012-1732-5

This paper describes a new type hydrogen sulfide (H 2 S) gas sensor using ionic liquid (IL). In this sensor, a reservoir for the IL was integrated on 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 shift in the resonant frequency. In this study, we fabricated and demonstrated the sensor using the lithium niobate (LiNbO 3 ) SAW resonator with the resonant frequency of 38 MHz. The integrated reservoir was filled by the IL 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim]-[PF 6 ]). As an experimental result, we observed the linear correlation between the frequency-shift and the exposure time of the sensor to the H 2 S gas.