Analytical modeling of a cantilever beam type vibration energy harvester with a lever mechanism

Energy need have increased in time, hence there is an obvious trend in seeking non-traditional energy sources, such as ambient mechanical vibrations. This paper focuses on the energy harvesting efficiency of piezoelectric-based cantilever beam type vibration energy harvesters. The aim is to increase efficiency by homogenizing the axial stress along the beam. For this purpose, a counter mass is attached to the beam via a simple lever mechanism. This way, an inertial force is applied on the beam, having a direction opposite of the inertia force of the tip mass, thereby obtaining a loading close to pure moment. A detailed analytical model for this structure is constructed. The analytical model is used to assess the effect of two design parameters on efficiency. It is shown that efficiency increases by means of the proposed method. The future work includes finite element analysis and experimental verification.