Research On Technology Of Piezoelectric Energy Harvesting

With the development of MEMS technology, IC technology and wireless sensing technologyin recent years, Electronic products such as the embedded system, the RF recognition system,wireless sensors as well as other implanted micro-sensors come into the age of integration,miniaturization and low power consumption. However, the traditional chemical batteries aredifficult to meet the needs of the energy supply of micro-devices because of the variousunfavorable factors such as bulk, short life and limited energy storage as well as environmentalpollution. Therefore, study on new power supply technology has become a urgent problem to besolved.A survey of the piezoelectric transducer technology at home and abroad is summarized. Theresearch achievements of the piezoelectric material technology, piezoelectric vibrator structuretechnology and energy storage technology are deeply discussed. Firstly, piezoelectric effectprinciple is introduced in detail. An equivalent circuit model about the energy output of thepiezoelectric transducer is established, by reference to the electromechanical couplingcharacteristics of the piezoelectric ceramic. The formulas of the resonance frequency,piezoelectric voltage and power output are deduced according to the model. Secondly, thestructure of the piezoelectric transducer has been optimized. Three piezoelectric models havebeen designed and the static analysis of the three piezoelectric models is carried out by using theANSYS finite element simulation software. The effect of resonant frequency on electricitygeneration of the piezoelectric transducer is analyzed. A piezoelectric transducer with widefrequency response is designed and a model of the piezoelectric transducer is established by theANSYS finite element simulation software. Then, the first and second order modes of vibrationand the curve of the amplitude-frequency are gotten via the analysis of the simulation. Finally, acomplete set of experimental test system of self-powered wireless sensor has been established.Electrical energy of piezoelectric transducer is supplied to the transmitter module of thetemperature sensor. The system can continue to send a temperature signal in the absence of anyexternal power supply.An optimization model of the piezoelectric energy harvester is put forward and the design ofbroadband-response piezoelectric energy harvester is carried out through the theoreticalderivation and the ANSYS finite element simulation in the paper. The feasibility of theharvesting program of vibration energy is verified through experiment. And research in the paper has contributed to the design of the vibration transducer which is applicable to the naturalenvironment and also has higher transfer efficiency.