Research On Material?preparation And Performance Of The Vibration Energy Harvester Based On Electrets

With the development of the intelligent system,the demand of the electronic equipment is increasing rapidly.The micro electro mechanical system is one of the electronic devices,which has the advantages of small size,light weight and small energy consumption.So it has aroused wide attention.The supply of energy is one of the key issues to make the micro electronic equipment widely used.The electret is a kind of functional dielectric material with oriented dipole and quasi permanent space charge.The electret material will form an electrostatic field in the external,when the electrode enters the space electric field,electrode induced charge,which is called the electret electrostatic effect.Due to the electrostatic effect,the electret is widely used in all kinds of sensors and micro energy harvester.As a product of micro energy technology,electret micro vibrated-harvester transforms the vibration energy into electric energy and has the advantages of long service life,no pollution to the environment and so on.At present,the research on the electret micro vibrated-generator is still in the preliminary stage,looking for electret Materials with excellent properties is the key.Thus this paper focus on the high performance polymer materials(FEP,THV,etc.)that are be used as the material of micro vibration generator power,explores the micro polymer electret charge distribution and charge storage property,Explored the influence of the size change of the graphics on the performance of the electret.Taking them as sensing material to make micro vibration energy collector,through theoretical simulation and experiments,and studied the factors that influence the power of the micro generator are obtained.The main research contents and results are as follows.(1)Aiming at the problems caused by the change of the size of the graphics,the performance of the system is reduced.With FEP film as the research object,grid aluminum electrode in 2 or 3 millimeter width were deposited on the FEP thin film surface.And the grid electric field distribution electret is prepared by using the corona and the thermal injection method respectively and its surface potential in samples showing transverse alternating high and low distribution phenomenon.The results show that when the sample is stored for 150 days after injection of two kinds of injection,the grid electric field distribution becomes clear and regular.The electric field in the aluminum electrode area is close to zero,and the potential of the area without aluminum is still high.The analysis shows the gate type electric field distribution could be gotafter evaporated aluminum electrode on FEP surface because of the difference in charge decay between FEP and metal aluminum surface.(2)In order to obtain the influence of the optimal injection electrode process on the gate shape charge storage,the effect of the fabrication process on the distribution of the grid shape in the polar body is studied.The results show that the initial surface potential of the sample with corona injection is higher than that of the thermal injection,but the decay rate is faster.The smaller the electrode width,the lower the initial surface potential,but the charge decay of the sample with different electrode width is similar.The higher the temperature,the higher the surface potential of the sample.(3)In order to overcome the potential decay of the FEP film after repeated vibration in many times,and the problem of the stability of the electrostatic field can not be maintained for a long time,the FEP/THV bilayer thin film was designed.In order to obtain the best dielectric properties of THV thin films,three kinds of THV(THV220?THV500 and THV815)thin films were prepared by high temperature melting and hot pressing,and measured the dielectric constant and dielectric loss.The results show that the dielectric constant of the three types of THV220,THV500,and THV815 are decreased with the increase of the test frequency.After thermal polarization,the dielectric constant of the electric power is decreased.Through the study,the FEP/THV double layer is found to have excellent storage performance,which can satisfy the micro vibration energy harvester.(4)Two kinds of vibration energy harvester for the vibration and lateral vibration of the longitudinal vibration and lateral vibration are designed.According to the principle of electrostatic induction,the model of the energy harvester in the polar body is put forward.Theoretical calculation and experiments were carried out to explore the factors affecting the output power of the micro vibration energy harvester.(4)the maximum output power of 4000 mW is obtained,and the vibration energy can be transformed to the electric energy,and the power supply of the LCD panel can be achieved.