Title :
New SAW humidity sensor using double-coated hygroscopic film
Author :
Furukawa, Shoji ; Obana, Masahiro ; Nomura, Tooru
Author_Institution :
Dept. of Comput. Sci. & Electron., Kyushu Inst. of Technol., Fukuoka, Japan
Abstract :
We propose a new surface acoustic wave (SAW) humidity sensor using double-coated hygroscopic film in order to improve the dynamic range of the relative humidity and the adhesion of the polymer film to (128° rot Y-X) LiNbO3 substrate. The effect of the physical constants of the material on the SAW propagation character has been investigated by both numerical calculation and experiment. As a result, it is found that the change in the SAW velocity (sensitivity) becomes larger (about 180%) by using the hygroscopic film having large stiffness constants, and the adhesion of the film is very much improved by using the double-coated structure
Keywords :
adhesion; humidity sensors; polymer films; surface acoustic wave sensors; LiNbO3; LiNbO3 substrate; SAW humidity sensor; adhesion; double-coated hygroscopic film; dynamic range; polymer film; relative humidity; stiffness constant; surface acoustic wave velocity; Acoustic propagation; Acoustic sensors; Acoustic waves; Adhesives; Delay lines; Dielectric substrates; Humidity; Piezoelectric films; Polymer films; Surface acoustic waves;
Conference_Titel :
Ultrasonics Symposium, 1995. Proceedings., 1995 IEEE
Conference_Location :
Seattle, WA
Print_ISBN :
0-7803-2940-6
DOI :
10.1109/ULTSYM.1995.495635
