Research On Energy Supply For Wireless Sensor Network Node Based On Piezoelectric Energy Harvesting Technology

Along with the construction of smart city, the monitoring of environmental problems and theestablishment of IOT, the wireless sensor network technology which is based on MEMS sensors,wireless communications and embedded control systems has achieved a rapid growth in recentyears. However, it has been a bottleneck to have its nodes maintaining a long term free operationin its further application and development. It would have a significant value and bright future andwhich is worthy of research if piezoelectric energy harvesting technology would be implementedto transform ambient vibration energy into available electrical energy which can effectivelysupply the running of wireless sensor network nodes.This paper centers on the piezoelectric energy harvesting technology, with emphasis on theenergy collection structure and processing circuit. By designing and optimizing the piezoelectricstructure, building energy conversion and storage circuit, the wireless sensor network nodes canbe power supplied. The main contents in this article are as follows:1. Introducing the principle of piezoelectric technology and the characteristics ofpiezoelectric material, on basis of which the mechanism of piezoelectric vibrator’s powergeneration would be discussed. With the usage of the piezoelectric ceramic material as theelement material and the selection of proper vibration mode and supporting manner, the energy ofthe surroundings shall be well collected under different environment.2. Cantilever piezoelectric vibrator is the typical structure of piezoelectric transducer device.On the foundation of the theoretical analysis and with the help of software ANSYS, this articlestudies the effects of the piezoelectric vibrator structural dimensions and material parameters toits power performance. Thereby it provides the theory evidence for the actual preparation ofpiezoelectric vibrator. And it also compares the internal resistance, the output voltage and outputpower in different cross-section layers, namely, rectangular, trapezoidal and triangle.3. On the other hand, it is further studied on the mechanical and electrical characteristics ofdisc piezoelectric vibrator by using a piezoelectric vibration equation theory to establish a finiteelement analysis model. To utilize the software ANSYS, the relationship between the structuralparameters and the output of frequency and voltage is accomplished. What’s more, this paper alsodiscusses the electromechanical properties of the oval piezoelectric vibrator and makes acomparative study with the disc piezoelectric vibrator.4. Meanwhile, the influence of the changing load to the output voltage and output powerbased on the classical energy harvesting circuit theory and PSPICE simulation analysis is clearly shown on this paper with statements of the operational principles and output characteristics ofseveral improved energy harvesting circuits. As for the selection of the energy storage element, ananalysis and comparison study is made between the capacitor and rechargeable batteries.