Research on Highly Sensitive Strain Sensing Element Based on Surface Acoustic Wave Resonator

SAW strain sensing element is an important part of SAW strain sensor. It is of great significance to design and analyze it. In this paper, the influence of piezoelectric substrate and electrode structure parameters on the performance of SAW strain sensing element is simulated and analyzed, using ST-quartz as piezoelectric material and aluminum as electrode material, a high-performance surface acoustic wave strain sensing element was designed, fabricated and measured. By analyzing the measured results, the strain sensitivity of frequency ( SSF ), strain coefficient of frequency SCF ) and temperature coefficient of frequency ( TCF ) of the SAW strain sensing element are 550.9Hz/ $\mu \varepsilon $ , 1.26 ppm/ $\mu \varepsilon $ and −1.22 ppm/°C respectively. The experimental results meet the design requirements well. This research provides a good guidance for the application of SAW strain sensor.