Title :
Multiple-frequency surface acoustic wave devices as sensors
Author :
Ricco, A.J. ; Martin, S.J.
Author_Institution :
Sandia Nat. Lab., Albuquerque, NM, USA
Abstract :
A multiple-frequency acoustic wave (MUFAW) device has been developed, fabricated, and tested on ST-cut quartz with nominal surface acoustic wave (SAW) center frequencies of 16, 40, 100, and 250 MHz. The four frequencies are obtained by patterning four sets of input and output interdigital transducers of differing periodicities on a single substrate. Such a device allows the frequency dependence of AW sensor perturbations to be examined, aiding in the elucidation of the operative interaction mechanism(s). Initial measurements of the SAW response to the vacuum deposition of a thin nickel film show the expected frequency dependence of mass sensitivity in addition to the expected frequency independence of the magnitude of the acoustoelectric effect. Measuring changes in both wave velocity and attenuation at multiple frequencies allows extrinsic perturbations such as temperature and pressure changes to be readily differentiated from one another and from changes in surface mass.<>
Keywords :
quartz; surface acoustic wave devices; ultrasonic transducers; vacuum deposition; 100 MHz; 16 MHz; 250 MHz; 40 MHz; Ni; ST-cut quartz; acoustoelectric effect; attenuation; extrinsic perturbations; frequency dependence; frequency independence; interdigital transducers; mass sensitivity; multiple-frequency surface acoustic wave devices; periodicities; surface mass; vacuum deposition; wave velocity; Acoustic sensors; Acoustic testing; Acoustic transducers; Acoustic waves; Frequency dependence; Frequency measurement; Nickel; Substrates; Surface acoustic wave devices; Surface acoustic waves;
Conference_Titel :
Solid-State Sensor and Actuator Workshop, 1990. 4th Technical Digest., IEEE
Conference_Location :
Hilton Head Island, SC, USA
DOI :
10.1109/SOLSEN.1990.109808
