Highly Sensitive Surface Acoustic Wave Flexible Strain Sensor

This letter presents a highly sensitive flexible strain sensor based on surface acoustic wave (SAW) working principle. The SAW strain sensor employs the piezoelectric single crystal PMN-PT thick film, which significantly improves the sensitivity of the strain sensor to 1243.49 Hz/mu epsilon. Meanwhile, the flexible strain sensor fabricated by the chemical and mechanical polishing process can realize a wide strain measurement range from -1000 to + 1000 mu epsilon. The repeatability of the device is also evaluated under the strain of 0 and 900 mu epsilon. The testing results demonstrate that this developed sensor is an excellent candidate for small stain measurement.