Evaluation of multiple transducers implementation in a magnetoelectric vibration energy harvester

Abstract

Abstract A novel magnetoelectric (ME) vibration energy harvester employing magnetostrictive and piezoelectric laminate composite transducers is presented for potentially powering wireless sensor systems. The harvester consists of two four-layered Terfenol-D/PZT laminate composite and a magnetic circuit composed by two parallel magnetic springs and two rectangular magnets. The repulsive forces are realized by a magnetic spring for more robustness. In order to realize a high power density, a multiple transducer design with a lateral configuration is proposed. The magnetic flux density and the induced displacement in the magnetostrictive layers are investigated by finite element analysis to determine the optimal relative position of the twin transducers at the static equilibrium. Furthermore, the output characteristics of the harvester are experimentally studied and compared to the case when only a single transducer is used. The experimental results show that the twin lateral converter can provide a higher power outcome especially if operated at resonance. In addition, doubling the amplitude of vibration from 0.5 mm to 1 mm leads to a voltage output which is four times higher at resonance.