SAW humidity sensor using dielectric hygroscopic polymer film
- 1 January 1994
- conference paper
- Published by Institute of Electrical and Electronics Engineers (IEEE)
- Vol. 1, 503-506 vol.1
- https://doi.org/10.1109/ultsym.1994.401638
Abstract
A surface acoustic wave (SAW) sensor for measurement of humidity is described. SAW devices have the ability to directly respond to the inertial mass and elastic mechanical properties of materials in contact with the device surface. Feature enables them to directly sense mass and mechanical properties of their environment. In this paper, we show a new SAW humidity sensor that uses the changes in the film permittivity rather than the mass. A dual SAW delay line fabricated on a piezoelectric substrate was coated with cellulose acetate. For a 128° YX LiNbO3 substrate, the hygroscopic polymer-coating caused a SAW velocity change of 0.33 m/s per 10% relative humidity. The response was linear in the range from 10% to 70% in relative humidity. The results suggest that the SAW humidity sensor using the dielectric interaction with the SAW electric field is quite promisingKeywords
This publication has 3 references indexed in Scilit:
- Measurement of Humidity Using Surface Acoustic Wave DeviceJapanese Journal of Applied Physics, 1992
- Surface acoustic wave gas sensor based on film conductivity changesSensors and Actuators, 1985
- Mechanism of operation and design considerations for surface acoustic wave device vapour sensorsSensors and Actuators, 1984