Title :
Characteristics of leaky SAW propagating along liquid/LiNbO3 /sapphire structure and its application to liquid sensor
Author :
Furukawa, Shoji ; Mizusaki, Kenji ; Shintani, Mikio ; Nomura, Tooru
Author_Institution :
Dept. of Comput. Sci. & Electron., Kyushu Inst. of Technol., Fukuoka, Japan
Abstract :
Liquid/LiNbO3/sapphire structure is proposed for high frequency liquid sensors, and the characteristics of leaky surface acoustic wave (leaky SAW) propagating along the layered-structure are examined by the numerical calculation based on the first-principle-equations. It is found that electromechanical coupling constant becomes maximum at Eulerian angles of (0,0,30+60n degree) (n: integer), whereas, shear horizontal component of the leaky SAW, which is coupled with the viscosity of the liquid, becomes large at other propagation directions. The maximum electromechanical coupling constant for glycerin/LiNbO3/(00.1) sapphire is about 1.3%, and the maximum leaky SAW velocity for water/LiNbO3 (10 μm)/(00.1) sapphire (30 MHz) is 5390 m/s. These results indicate that this layered-structure is useful for high frequency liquid sensors
Keywords :
density measurement; lithium compounds; sapphire; surface acoustic wave sensors; surface acoustic waves; viscosity measurement; 10 micron; 30 MHz; 5390 m/s; Eulerian angles; Lame constants; LiNbO3; LiNbO3-Al2O3; density change; electromechanical coupling constant; first-principle-equations; glycerin/LiNbO3/sapphire; high frequency liquid sensors; layered-structure; leaky SAW propagation; liquid/LiNbO3/sapphire structure; shear horizontal component; viscosity sensors; water/LiNbO3/sapphire; Acoustic sensors; Acoustic waves; Conductivity; Frequency; Propagation losses; Sensor phenomena and characterization; Substrates; Surface acoustic waves; Thin film sensors; Viscosity;
Conference_Titel :
Ultrasonics Symposium, 1997. Proceedings., 1997 IEEE
Print_ISBN :
0-7803-4153-8
DOI :
10.1109/ULTSYM.1997.663056
