Generating characteristics of an eye-shaped piezoelectric harvester

Abstract

In this paper, a newly designed piezoelectric harvester which generates electricity by using tensions on the device is proposed. The device is named as an eye-shaped harvester. The eye-shaped harvester consists of a rectangular ceramic and two elastic body plates are attached to each surface of the ceramic. If tensions are given at both ends of the elastic body, the tensions are changed to pressures on the ceramic through a form change of the elastic body and the piezoelectric effect occurs at the ceramic to generate electricity. Because of the structure of this eye-shaped generator if can be easily in various places where tensions existing. This harvester has a relatively high durability, because the forces are not directly applied to the ceramic. The dependences of the generating output characteristics of the eye-shaped piezoelectric harvester on the ceramic size and at the materials of the elastic body were studied. The resonance and the output characteristics of the generator were analyzed by using a finite-elementmethod program. Generators were fabricated on the basis of the analytical results and were attached to a frequency-controllable vibrator to measure the output characteristics. Also, the experimental results were compared with the simulated results. The output voltages of the generator were increase when ceramic is width was decreased. When the ceramic’s length was decreased found to, the resonance frequency of the generator was decreased. For different materials of the elastic body, the highest voltage was obtained at the lowest resonance frequency when brass was used.