Piezoelectric PZT fiber composite as a low frequency vibration sensor

The recently developed macro fiber composites (MFCs) with in-plane aligned PZT fibers embedded in polymeric thick films combine the excellent piezoelectric property of PZT fibers and the flexibility of polymer, which are suitable for many smart materials and intelligent structure applications. In this paper, we present both theoretical and experimental studies of a low frequency vibration sensor using the PZT fiber composite in a simple cantilever structure. Global parameters of the PZT fiber composite were substituted into the lumped and distributed parameter models for cantilevered piezoelectric unimorph vibration sensors to predict the voltage output sensitivity and frequency response. Experimental studies were carried out and the predicted performance of the low frequency vibration sensor agrees well with the experimental results. With excellent flexibility, tailorable elastic, dielectric and piezoelectric properties, and large time constant, the PZT fiber composite works well as vibration sensor that has very low resonant frequency.