Macroscopic theory of surface acoustic wave gas microsensors
- 6 January 2003
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- p. 585-589 vol.1.
- https://doi.org/10.1109/ultsym.1988.49444
Abstract
Recently it has been experimentally demonstrated (see J.F. Vetelino et al., 1987) that a surface acoustic wave gas microsensor can detect concentrations of certain gases in the parts per million to parts per billion range. Here, a theoretical model is presented which is capable of predicting the change in sensor response as a function of gas concentration. The geometry of interest consists of a metal oxide film on a piezoelectric substrate. It is assumed that on exposure to a gas, the most significant change in the film is the creation of free charge carriers which cause the film to change from a dielectric to a semiconductor. The free carriers then interact with the electric field associated with the acoustic wave traveling at the film-piezoelectric interface, causing a corresponding change in the sensor response. Results are presented for a tungsten trioxide film on a lithium niobate substrate which has been exposed to hydrogen sulfide gas. The theoretical results are compared to experimental data.<>Keywords
This publication has 5 references indexed in Scilit:
- Hydrogen Sulfide Surface Acoustic Wave Gas DetectorIEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 1987
- Processes involved at the chemical interface of a saw chemosensorSensors and Actuators, 1987
- Surface acoustic wave gas sensor based on film conductivity changesSensors and Actuators, 1985
- Simple theory of acoustic amplificationIEEE Transactions on Sonics and Ultrasonics, 1971
- Linear and Nonlinear Attenuation of Acoustic Surface Waves in a Piezoelectric Coated with a Semiconducting FilmJournal of Applied Physics, 1970