A self-powered wireless sensor node for structural health monitoring

Abstract

We developed a self-powered wireless autonomous Structural Health Monitoring (SHM) sensor node using a Texas Instruments MSP430 evaluation board. The sensor node employs a PZT (Lead Zirconate Titanate) based impedance method, which saves power by eliminating a digital-to-analog-converter (DAC) for generation of an excitation signal and an analog-to-digital converter (ADC) for sensing the response. The sensor node wakes up at a predetermined interval, performs an SHM operation, and reports the result to the host computer wirelessly. The sensor node consumes only 0.3 J and is powered up by the energy harvested from vibrations, often available from infrastructures. The power management circuit integrated with a piezoelectric cantilever with the size of 50 mm x 31.8 mm generate up to 2.9 mW under 0.5g (rms) base acceleration, which is sufficient to run an SHM operation on every two minutes.