Nonlinear Dynamics and Power Generation on a New Bistable Piezoelectric-Electromagnetic Energy Harvester

This paper focuses power generation and nonlinear dynamic behaviors on a new bistable piezoelectric-electromagnetic energy harvester. Three different kinds of piezoelectric cantilever beam structures, which include the monostable piezoelectric cantilever beam, the bistable piezoelectric cantilever beam with spring and magnet, and the bistable piezoelectric cantilever beam with spring, magnet, and coil, are designed. The power generation efficiency and dynamic behaviors for each structure are experimentally studied, respectively. Due to the spring introduced, the system easily goes through the potential barrier. Experimental results show that the power generation structure of the bistable piezoelectric-electromagnetic harvester can vibrate between two steady states in a wider range of the frequency. Therefore, the effective frequency bandwidth is broadened about 2 Hz when the spring is introduced under the condition of the suitable magnetic distance. Comparing with the power generation efficiency for three different kinds of structures, it is found that the bistable piezoelectric-electromagnetic harvester has the optimum characteristics, which include the optimal magnetic distance of 15 mm, the optimal load of 8 MΩ, and the parameters variation law of coils. For this structure, the influences of the external excitation and the magnetic distance on the output voltage and dynamic behaviors of the system are examined.

Non-Linear Dynamics and Optimization of a Harvester–Absorber System

In this paper, we propose a novel concept of a harvester-absorber system. The idea is based on usage of the dynamic absorber for energy harvesting. The device consists of three elements: a main system (damped body), a pendulum (tuned mass absorber) and an electromagnetic harvester. The ultimate goal of this investigation is to achieve simultaneous mitigation of vibrations and energy harvesting. We show the dynamics of the system and ranges of parameters where we observe good damping properties and high energy recovery. Additionally, an optimization of the harvester device parameters has been performed.