Improved Magnetic Interaction for Frequency Up-Conversion

This chapter presents a technique to improve the efficiency of the magnetic pluckingMagnetic plucking in piezoelectric vibration energy harvesting by means of the manipulation of magnetic forcesMagnetic forces. First, the technique is presented through a description of the working principle from an intuitive point of view based on a literature study. Then, a computational study of the magnetic forceMagnetic forces is proposed on shielded magnets with additional ferromagnetic material according to a proposed technique. Time domain simulations are then carried out on a dynamical system composed of seismic mass and a piezoelectric oscillator to evaluate the benefit of the technique. Finally, an experimental investigation is presented on NdFeB permanent magnets, to confirm the proposed concept.