Based On The Electromagnetic Effect The Vibration Source Of Energy For Mems Micro Power Supply Design

Micro power is one of the important research area in the development of MEMS technology, and it is an key component in realizing the autonomous working of wireless communication systems, portable mobile products and Internet of Things (IOT).In this paper, A electromagnetic MEMS micro power system for vibration energy harvesting over a predetermined low frequency vibration environment is designed.The electromagnetic MEMS micro power system is consist of two parts: one is for vibration energy harvesting, the other one is for energy transformation. The research contents and research results in this paper is presented as follows.1) Part for vibration energy harvesting:The vibration model and the vibratory response of this part are analysed theoretically, and the mentality of designing is pointed out, which is to maximize the vibration amplitude and acquire much more vibration energy, the micro power system should work at resonance and the damping ratio should be low. Considering the feature of low frequency vibration environment, a kind of structure with a cantilever beam is designed and optimized to matche the excitation frequency and to decrease the damping ratio. The parameter model of the cantilever beam by use of the ANSYS software is set up and analyzed to verify the results, include the static analysis, the model analysis and the resonant analysis.2)Part for energy transformation:the Electromagnetic induction principle, the output voltage and the output power of the micro power system are analysed theoretically, and the mentality of designing is pointed out, which is to acquire much more output voltage and output power, the magnetic density and the ampere-conductors should be enough. A kind of structure for energy transformation with permanent magnets and ciols is designed and optimized, include material selection of the permanent magnets, physical design of the moving part, the theoretical arithmetic of the variable relations between the resistance, number of windings and the dimensions of the coils. The magnetic field distribution produced by the permanent magnets and the induced voltage in the moving coils is modeled and analyzed by use of the Ansoft Maxwell software, and the output voltage is calculated.3) After optimal design of the two parts of the micro power system, the parameters of this micro power system are as follows. The suitable frequency of vibration environment is 30～50Hz. When the maximum amplitude of the moving part is 0.2 mm, the output voltage is 1.66 mV. And when the load resistance is 50Ω, considering the internal resistance of micro power system, the output power is calculated as 36.8nW.