Highly Sensitive Wireless Sensor Node using Surface Acoustic Wave Devices for Structural Health Monitoring

Abstract

A wireless node of strain sensor was developed for structural health monitoring. Surface acoustic wave (SAW) oscillators were used as sensor heads of the system, and can linearly detect the strain of 10^-5 to 10^-6 order. In the developed sensor node, a mixer chip and a communicator were integrated on the board for temperature compensation and construction of sensor mesh network. We practically applied the developed sensor nodes to measurement of the static deformation in the metal plate, and successfully detected the deformation distribution. In this experiment, power consumption of each node was 190 µW in sleep mode and 50 mW in data transmission mode.