Research On Nonlinear Piezoelectric Energy Harvester Based On Elastic Amplification Technology

With the rapid development of integrated circuits,microelectronic devices have become mainstream,and the development of low-power design technologies has also led to the reduction of power consumed by microelectronic devices.At present,microelectronic devices are mostly powered by batteries,but the battery itself has defects such as limited service life,high replacement cost,difficulty in miniaturization,pollution to the environment,etc..Also,when the number of devices is large or the device is placed remotely,replacing the battery or charging the device will be not easy.Therefore,it is a new research to power the microelectronic equipment from the environment instead of from the traditional battery.Vibration energy harvesting is one of a common method of environmental energy harvesting,and obtaining energy from walking or jumping is a more practical and convenient way in environmental capture energy.In this paper,the traditional simply supported beam structure is improved,and a piezoelectric simply supported beam energy absorbing device suitable for human captive energy is designed.Firstly,according to the basic principle of piezoelectric effect,the principle of piezoelectric energy harvester and the piezoelectric equation is briefly introduced,and focus on analyzing and explaining the characteristics of piezoelectric simply supported beams.The mode shape equation of the piezoelectric simply supported beam with spring amplifier is established.Secondly,the mathematical model of the piezoelectric harvesting structure with spring amplifier is established.Simulink simulation is carried out according to the calculated natural frequency and structural parameters,and analyze the influence of relevant parameters on the power generation performance.Thirdly,using ANSYS and COMSOL finite element simulation software to simulate the piezoelectric harvesting structure based on elastic amplification technology,and compare the result with Simulink simulation to verify the correctness of theoretical simulation;carry out other parameters not involved in theoretical simulation to analyze the effect on the power generation performance of piezoelectric structures.Based on the nonlinear characteristics of magnets,an improved nonlinear piezoelectric energy-capture structure based on spring amplification technology is designed and finite element simulation is carried out.The data shows that the improved piezoelectric structure has better power generation performance than before.Finally,a piezoelectric capacitor device is fabricated,an experimental study is performed,and an energy harvesting circuit is designed for energy harvesting.The results show that the nonlinear structure produces better voltage and frequency bandwidth than the linear structure,so the improved piezoelectric energy-capacitor structure has the best power generation performance.The piezoelectric harvesting structure is connected to the collecting circuit,and the LED light of the collecting circuit is bright.After actual measurement,in order to achieve a voltage of 5V across the small lamp,the nonlinear structure requires 48s,which requires less time than the linear structure,so that the small lamp can be lit more quickly.At the same time,after calculation,the piezoelectric energy harvesting device improved in this paper generates about 11.69mW,and the output power per unit volume of the piezoelectric beam is 8.85?W/mm~3,which is 130%higher than the output efficiency of the pure piezoelectric simply supported beam structure under the same structure.So,the improved nonlinear structure is enough to charge for low-power products.Therefore,in practical applications,the structure proposed in the paper can be used for charging small lamps on children's luminous shoes,flashing sports shoes,etc.,and can also be used in shoes to charge micro-power products in emergency situations.