A vibration energy harvester using magnetostrictive/piezoelectric composite transducer
ABSTRACT An energy harvester is presented to convert ambient mechanical vibration into electrical energy. The harvester consists of a cantilever beam, a magnetic circuit and a magnetostrictive/piezoelectric laminate magnetoelectric (ME) transducer. The magnetic circuit is arranged on the free end of the beam and produces a concentrated flux gradient. 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. The nonlinear vibration performances of the harvester are studied using the Lindstedt-Poincare method, and the electrical-output performances of the harvester at resonance are analyzed. A prototype has been 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 frequency of 51 Hz.