A Compressive-Mode Wideband Vibration Energy Harvester Using a Combination of Bistable and Flextensional Mechanisms

In this paper, a compressive-mode wideband vibration energy harvester using a combination of bistable and flextensional mechanisms is proposed. The structure consists of a cantilever with a magnet fixed at its free end, and a flextensional actuator with a magnet fixed at its free end. A theoretical model is developed to characterize the compressivemode wideband vibration energy harvester. Both simulations and experiments are carried out to validate the design and analysis of the compressive-mode wideband vibration energy harvester. The results show that the device can work in broadband, and the piezoelectric constant d31 can be enlarged 134 times. The experimental results also indicate that the harvester can generate the power about 31 mu W with the resistive load 390 k Omega, while the magnetic pressure is 2.9 N. A developed design including two flextensional actuators symmetrically arranged is also presented. The experimental results show that the two flextensional actuators in the developed design can harvest more energy than one flextensional actuator in the primal design.