Wideband vibro-impacting vibration energy harvesting using magnetoelectric transduction

Abstract

This article reports on proof-of-concept experimental work carried out to demonstrate a wideband vibro-impacting energy harvesting approach based on a magnet/bearing arrangement coupled with a magnetoelectric transducer. The harvesting arrangement uses a Terfenol-D/Pz27 laminate transducer (disc with radius 5 mm) positioned between an oscillating spherical chrome-steel bearing and a rare earth magnet. The oscillating bearing steers magnetic field through the magnetoelectric transducer, generating an oscillating charge that can be harvested. A vibro-impacting arrangement between the oscillating bearing (radius 12.7 mm) and a pair of aluminium mechanical stops is designed to produce a wideband frequency response. For a 434 mG host acceleration, the vibro-impact mechanism produced a bandwidth of ∼7.2 Hz (between 6 and ∼13.2 Hz). The issue of damage to the mechanical stops caused by the vibro-impacting process is also explored and was demonstrated experimentally and theoretically to be inconsequential. This non-optimized wideband harvesting approach has demonstrated a generated power of 3.3 µW from a root mean square host acceleration of 180 m-g at 8.0 Hz.