Improving energy harvesting in a tri-stable piezomagnetoelastic beam with two attractive external magnets subjected to random excitation

A novel tri-stable energy harvester (TEH) is developed to improve the efficiency of harvesting vibration energy. The corresponding dynamical model was established, and its motion equations were derived. The potential energy shows that the TEH owns shallower and wider potential wells than bi-stable energy harvester (BEH). The bifurcation diagrams of stable equilibrium positions show that the TEH can experience mono-stable, bi-stable, and tri-stable states by altering the separation and gap distances. The simulations were carried out. Validate experiments were performed for several random excitation levels. The results verify that the TEH can realize interwell oscillation easier and generate a dense of high output voltages. So the presented TEH is a promising alternative for improving the energy harvesting performance.