Vibration energy harvester based on magnetoelectric transducer

An energy harvester is presented to scavenge energy from ambient vibrations using magnetostrictive/piezoelectric laminated magnetoelectric (ME) transducer. A cantilever beam is employed as the vibration sensitive element of the harvester, and a magnetic circuit made up of four NdFeB magnets is placed on the free end of the beam. Since the magnetic circuit produces a concentrated flux gradient in the air gap, the ME transducer can induce large magnetic field variations in the low level vibration, thus high output power can be obtained. Based on the equivalent magnetic charge theory, the magnetic field distribution of the air gap and the magnetic force of the magnetic circuit are analyzed, and the nonlinear vibration performance of the harvester is studied using the Lindstedt-Poincare method. The mechano-magneto-electric performance of the harvester at resonance is analyzed by combining the vibration equation of the harvester with the magnetoelectric characteristics of the ME transducer. The experimental results verified the analytical results, and a prototype produces a power of 112.4 mu W for an acceleration of 0.5g at its resonant frequency of 33 Hz.