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.