Evaluation of a novel piezoelectric bridge transducer

A novel piezoelectric bridge transducer was developed for an energy harvesting application from vehicle induced loading on pavement. A unique electrode design enables the PZT to be poled horizontally, enabling the d ₃₃ piezoelectric coefficient to be utilized by the transducer, enhancing energy output. The transducers were fabricated and assembled in an energy harvesting module and the output energy and power was measured under simulated vehicle loading. In this work, the effective piezoelectric coefficient of the transducer has been measured using the direct piezoelectric effect as well as the converse piezoelectric effect to evaluate the transducer for an actuator or sensor application. The effective d ₃₃ measured by the direct method is 19,000 pC/N and the g ₃₃ is 2150 × 10 ^-3 Vm/N. The reliability and cycles to failure of the transducer design is studied and the transducers are evaluated after 50,000 loading cycles. Inconsistency in the epoxy layer thickness has been identified as the cause of premature failure.