Design And Characteristic Analysis Of Vibration Energy Acquisition Device Based On Piezoelectric Material

In recent years,the development of wireless communication technology and sensor monitoring technology is becoming more and more intelligent,and the energy supply problem of MEMS system,on-chip control system and other low energy consumption systems is becoming increasingly serious.Aiming at this problem,this paper studies the cantilever piezoelectric energy acquisition device with green,pollution-free,strong sustainability and good environmental adaptability.It is an electromechanical coupling system that converts the vibration energy in the environment into electrical energy.It is the most widely studied autonomous power supply technology of wireless sensor network.Based on this feature,it has attracted extensive attention of relevant technical personnel in various fields^[1].For the sake of reduce the inherent frequency of the cantilever piezoelectric energy collection device,improve the energy collection efficiency,and provide long-term stable power supply for the low energy consumption monitor in the environment.In this paper,the cantilever piezoelectric vibrator is studied as the main structure.The specific research contents are as follows.（1）In this paper,the research status of cantilever piezoelectric energy harvester is briefly introduced,and the development trend of piezoelectric energy harvester is analyzed from different aspects.Based on the power generation principle of the traditional cantilever piezoelectric energy collector,the influence of the inherent characteristics of the piezoelectric vibrator on the overall output performance of the energy collector is analyzed.（2）The basic model of piezoelectric energy harvester is established based on the double crystal series cantilever piezoelectric vibrator.The structure size of the cantilever beam piezoelectric vibrator was optimized by the orthogonal experiment method.The effects of frequency response,external load and external excitation acceleration on the output performance of the piezoelectric energy harvester are analyzed by COMSOL simulation.（3）In order to achieve the design goal of low frequency,wide band and high output,this section studies the output characteristics of rectangular,trapezoidal and triangular piezoelectric oscillators with the same base,equal height and the same thickness.The results show that:Under the same conditions,the output performance of the rectangular piezoelectric vibrator is the best,and the output power can reach 30.95m W;in order to solve the problem of narrow acquisition frequency band of single cantilever piezoelectric vibrator,this section combines 8 piezoelectric oscillators with similar natural frequencies into composite cantilever piezoelectric vibrator,which widens the working frequency band of the collector to 40.441Hz～50.459Hz,and enhances the piezoelectric energy collector Adaptability to vibration environment.（4）The cantilever piezoelectric vibrator was fabricated and the experimental platform of vibration energy acquisition was built.The output performance of single cantilever piezoelectric vibrator and composite cantilever piezoelectric vibrator array was tested.The experimental results show that the working bandwidth of the composite cantilever piezoelectric vibrator is much larger than that of the single cantilever piezoelectric vibrator,and the maximum output power of the composite cantilever piezoelectric energy collector can reach 169.08m W in the frequency band of39Hz～48Hz.And through the LED lamp experiment,it is proved that the piezoelectric energy harvester can provide a continuous and stable power supply for the low energy consumption monitoring element.