A Thickness Shear Mode Zinc Oxide Liquid Sensor with Off-axis Excitation

Author

Corso, Christopher D. ; Dickherber, Anthony ; Hunt, William D.

Author_Institution

Georgia Inst. of Technol., Atlanta

fYear

2007

fDate

28-31 Oct. 2007

Firstpage

930

Lastpage

933

Abstract

A thickness shear mode acoustic sensor is developed based on a typical longitudinal mode electrode configuration through the use of a tuned acoustic mirror. The coupling of the electric field to a thickness shear mode occurs because of an off-axis electric field produced near the periphery of the top electrode. The existence of a lateral electric field component is verified through finite element simulations. The fabricated devices exhibit a Quality factor (Q) on average of 80 with an acoustic velocity of-3,086 m/s at 2.0 GHz. Sensor experiments are performed under liquid loading conditions, using glycerol-water solutions. The thickness shear mode resonance is monitored in real-time for a shift in frequency indicating sensitivity to the density-viscosity product. The highly sensitive mass sensor has the potential for use in biological sensing applications.

Keywords

Q-factor; acoustic resonators; chemical sensors; finite element analysis; mirrors; zinc compounds; acoustic sensor; density viscosity product; finite element simulations; glycerol water solutions; lateral electric field component; off axis electric field; shear mode resonance; thickness shear mode; top electrode; tuned acoustic mirror; zinc oxide liquid sensor; Acoustic devices; Acoustic sensors; Biosensors; Couplings; Electrodes; Finite element methods; Mirrors; Q factor; Resonance; Zinc oxide;

fLanguage

English

Publisher

ieee

Conference_Titel

Sensors, 2007 IEEE

Conference_Location

Atlanta, GA

ISSN

1930-0395

Print_ISBN

978-1-4244-1261-7

Electronic_ISBN

1930-0395

Type

conf

DOI

10.1109/ICSENS.2007.4388555

Filename

4388555