The Characteristic And Experimental Research Of Multi-resonant Frequency Piezoelectric Vibration Energy Harvesting Structure

In recent years, the concept of "new energy" is coming into the focus of attention among the community and engineers. The research of all kinds of energy harvesting methods such as solar, wind, nuclear has made great progress and is widely used. At the same time, the rapid development of MEMS makes ever-increasing demands of micro-power devices. But most energy harvesting methods are difficult to be applied to MEMS due to structure size and terms of usage. Under this circumstance, vibration energy harvesting is getting increasing attention owing to its wide variety of sources and easy to harvest. But the traditional piezoelectric vibration energy harvesting structure has only one resonant frequency and is poor in generation performance and adaptability of work environment. So this thesis studied multi-resonant frequency piezoelectric energy harvesting technology in the following four aspects.Firstly, the mathematical model of piezoelectric vibrator is established to obtain its output characteristics of voltage and charge, which provides a theoretical basis for designing piezoelectric structure.Secondly, using finite element analysis software ANSYS 11.0, the relations of geometric parameters of the cantilever beam versus natural frequency and output voltage are obtained through static analysis, modal analysis and harmonic analysis. The simulation results correspond with theoretical calculation and prove the mathematical model.Thirdly, the parameters of multi-resonant frequency piezoelectric energy harvesting structure are optimized and its generation capacity is analyzed. Then an experimental device is designed and fabricated.Finally, the hardware and software experimental system is designed and realized. The experimental results showed that multi-resonant frequency piezoelectric energy harvesting structure expands the range of frequency response and has good generation performance.