A bi-axial magnetoelectric vibration energy harvester

This article reports on a vibration energy harvesting approach that uses a magnetoelectric (ME) transducer to harvest energy from bi-axial vibrations. A bi-axial oscillator is created using a permanent-magnet/ball-bearing arrangement, which has the added benefit of permitting a relatively compact design. The magnet produces a bi-axial restoring force on the bearing, and as the bearing oscillates, it steers magnetic field through the transducer thereby producing an oscillating charge that can be harvested. A simple laboratory demonstrator of a bi-axial ME harvester was created using a magnetostrictive/piezoelectric laminate transducer, and was shown to produce a peak rms power of 121 μW from an rms acceleration of 61 mG at 9.8 Hz.