Strain Sensitivity of Epoxy-Quartz Packaged Saw Strain Sensors

Abstract

A SAW strain sensor with new simplified Epoxy-Quartz packaging is analyzed in this paper. The strain sensitivity of sensors with Epoxy-Quartz Package is calculated with perturbation theory and finite element method theoretically. The sensitivity is close to the sensitivities of traditional AQP, which are 3.20 ppm / με and 3.32 ppm / με respectively. Then an Epoxy-Quartz Packaged 433MHz SAW strain sensor is fabricated by using the epoxy EP-4 adhesive. An experimental platform is set up and the strain sensitivity of Epoxy-Quartz Packaged is measured at 20 °C. The experimental results indicate that strain sensitivity of Epoxy-Quartz Packaged is 2.51 ppm / με, which almost agrees with theoretical results. Therefore, a new simplified package for SAW strain sensor with a relatively high strain sensitivity is verified in this paper.