Wireless Calibration of a Surface Acoustic Wave Resonator as a Strain Sensor

In this paper, calibration data for a single one-port surface acoustic wave (SAW) resonator strain sensor fabricated on 36 (AT) quartz is presented. This substrate was chosen as it is traditionally associated with temperature stability in SAW resonator design. To investigate the sensor as a general-purpose strain sensing element the sensors were bonded using standard adhesives and calibrated using a special-purpose test apparatus and a repeatable testing methodology. Bonding effects and thermal sensitivities are empirically investigated. Longitudinal and transverse strain sensitivities at a range of temperatures are presented as well as the variation in sensor sensitivity as function of alignment angle to applied strain.