Micromachined surface acoustic wave sensor for detecting inert gases

S. Ahuja, Mark C Hersam, C. Ross, H. T. Chien, A. C. Raptis

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Surface acoustic wave (SAW) sensors must be specifically designed for each application because many variables directly affect the acoustic wave velocity. In the present work, we have designed, fabricated, and tested an SAW sensor for detection of micromachined interdigitated transducers (IDTs) and delay lines fabricated by photolithography on a single Y-cut LiNbO3 substrate oriented for Z-propagation of the SAWs. One set is used as a reference and the other set employs a delay line coated with a titanium-based thin film sensitive to electrical conductivity changes when exposed to metastable states of He. The reference sensor is used to obtain a true frequency translation in relation to a voltage controlled oscillator. An operating frequency of 109 MHz has been used, and the IDT finger width is 8 μm. Variation in electrical conductivity of the thin film at the delay line due to exposure to He is detected as a frequency shift in the assembly, which is then used as a measure of the amount of metastable He exposed to the sensing film on the SAW delay line. A variation in the He pressure versus frequency shifts indicates the extent of the metastable He interaction.

Original languageEnglish
Title of host publicationProceedings of the IEEE Ultrasonics Symposium
EditorsM. Levy, S.C. Schneider, B.R. McAvoy
PublisherIEEE
Pages435-438
Number of pages4
Volume1
Publication statusPublished - 1996
EventProceedings of the 1996 IEEE Ultrasonics Symposium. Part 2 (of 2) - San Antonio, TX, USA
Duration: Nov 3 1996Nov 6 1996

Other

OtherProceedings of the 1996 IEEE Ultrasonics Symposium. Part 2 (of 2)
CitySan Antonio, TX, USA
Period11/3/9611/6/96

Fingerprint

Electric delay lines
Inert gases
Surface waves
Acoustic waves
Sensors
Transducers
Thin films
Variable frequency oscillators
Acoustic wave velocity
Photolithography
Titanium
Substrates
Electric Conductivity

ASJC Scopus subject areas

  • Engineering(all)

Cite this

Ahuja, S., Hersam, M. C., Ross, C., Chien, H. T., & Raptis, A. C. (1996). Micromachined surface acoustic wave sensor for detecting inert gases. In M. Levy, S. C. Schneider, & B. R. McAvoy (Eds.), Proceedings of the IEEE Ultrasonics Symposium (Vol. 1, pp. 435-438). IEEE.

Micromachined surface acoustic wave sensor for detecting inert gases. / Ahuja, S.; Hersam, Mark C; Ross, C.; Chien, H. T.; Raptis, A. C.

Proceedings of the IEEE Ultrasonics Symposium. ed. / M. Levy; S.C. Schneider; B.R. McAvoy. Vol. 1 IEEE, 1996. p. 435-438.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Ahuja, S, Hersam, MC, Ross, C, Chien, HT & Raptis, AC 1996, Micromachined surface acoustic wave sensor for detecting inert gases. in M Levy, SC Schneider & BR McAvoy (eds), Proceedings of the IEEE Ultrasonics Symposium. vol. 1, IEEE, pp. 435-438, Proceedings of the 1996 IEEE Ultrasonics Symposium. Part 2 (of 2), San Antonio, TX, USA, 11/3/96.
Ahuja S, Hersam MC, Ross C, Chien HT, Raptis AC. Micromachined surface acoustic wave sensor for detecting inert gases. In Levy M, Schneider SC, McAvoy BR, editors, Proceedings of the IEEE Ultrasonics Symposium. Vol. 1. IEEE. 1996. p. 435-438
Ahuja, S. ; Hersam, Mark C ; Ross, C. ; Chien, H. T. ; Raptis, A. C. / Micromachined surface acoustic wave sensor for detecting inert gases. Proceedings of the IEEE Ultrasonics Symposium. editor / M. Levy ; S.C. Schneider ; B.R. McAvoy. Vol. 1 IEEE, 1996. pp. 435-438
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