Investigation Of A Low-frequency Piezoelectric And Electrostatic Hybrid Vibration Energy Harvesting Technology

With the wireless’ sensor network developing very quickly,it requires power supply that is low and stable.But traditional batteries can’t meet the demand because of big-volum,short-life time and often changeable.Especially,they can’t be used in rural areas where humans can’t be there.Vibration energy harvesting from enviorment can solve the problem.This paper works on piezoelectric vibration energy harvester(VEH)and electrostatic VEH.Different mathematic models are set up according to the basic linear mass-spring-damping system.Moreover,it presents a new hybrid VEH,which has function of piezoelectric VEH and electrostatic VEH.Meanwhile,three kinds of hybrid energy harvester based on nonlinear mechanical structures and double capacitors are designed.It presents two important structure parameters of VEH,including the mechanical quality factor.It analyses static and mode of structure by using Ansys software and gets the relationship between the width of mass and thickness of beam with the maximum amplitude and natural frequency.Outputs of large-scale prototype and MEMS VEH are simulated by MATLAB/SIMULINK based on mathematic model.It shows from the results that the piezoelectric VEH works best in the low-frequency environment among all kind of VEHs and electrostatic VEH has better performance in the low-frequency vibration environment.In low-frequency vibration environment,the hybrid VEH has the better output than piezoelectric VEH and electrostatic VEH with the same structure.Based on the theoretical analysis,we fabricate large-scale prototype to verify the nonlinear energy output and make a result analysis.At last,it shows MEMS process flow to manifacture the hybrid VEH.It analyses some importort processes.The three layers glass/SOI/glass bonding process is fabricated in two stages.