Modeling, characterization and fabrication of vibration energy harvester using Terfenol-D/PZT/Terfenol-D composite transducer

Vibration energy harvesting has been receiving a considerable amount of interest as a means of powering wireless sensors and low-power devices. In this paper, an energy harvester is presented to convert ambient mechanical vibration into electrical energy employing the Terfenol-D/PZT/Terfenol-D laminate magnetoelectric (ME) transducer. The harvester uses four magnets arranged on the free end of a cantilever beam. The magnets produce a concentrated flux gradient in the air gap, and the ME transducer is placed in the air gap between the magnets. When the harvester is excited, the magnetic circuit moves relative to the ME transducer. The ME transducer undergoes magnetic field variations and produces a power output. An analytical model is developed to analyze the nonlinear vibration and electrical-output performances of the harvester. A prototype is fabricated and tested. The experimental results are in agreement with the analytical results. The prototype produces a power of 2.11 mW for an acceleration of 1 g at resonant frequency of 51 Hz.