SAW-RFID temperature and strain sensors on metallic substrates

Abstract

Herein we present new surface acoustic wave (SAW) sensors integrating a radio-frequency identification code and directly fabricated on metal substrates with piezoelectric thin films. Those sensors overcome by construction the main weakness of strain sensors, namely the need of bonding with adhesives on the monitored equipment. The proof of concept was carried out using a SAW device based on a ZnO/Titanium multilayer structure. Sensors were characterized both in temperature (from 25 to 300 °C) and under strain (from 0 to 1800 µε). Results have shown a good linearity of the sensors’ responses, a good stability at high temperature and a good strain sensitivity.