A surface acoustic wave (SAW) sensor for measuring environment is presented. SAW devices respond to changes in the mass on its surface with a shift in frequency, and offer many attractive features for applications as a gas and liquid phase sensor. In the most gas phase sensor, the device surface is coated with a thin selective film. In this paper a SAW delay line coated with self-assembled (SA) film has been used as environment sensor. A dual delay line was fabricated on a single lithium niobate (128° Y cut X propagating LiNbO3) substrate and the propagation path was coated with the selective polymer film deposited by SA transfer technique. The polystyrene sulfonic acid sodium was used as a gas sensing material. Due to sorption of molecules, the electrical conductivity of the SA film changes. The effects caused to reduce the velocity of the SAW. Experimental results showed that the SAW velocity change was quite linear in proportion to the concentration of organic gases. Rapid and totally reversible responses were obtained by using a SA monolayer film.
|ジャーナル||Proceedings of the IEEE Ultrasonics Symposium|
|出版ステータス||Published - 1998 12 1|
|イベント||Proceedings of the 1998 International Ultrasonics Symposium - Sendai, Miyagi, Jpn|
継続期間: 1998 10 5 → 1998 10 8
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