Development Of Fractal Piezoelectric Ceramics Vibration Transducer

With the development of science and technology,various forms of energy harvesting technology were gradually rising.As one of the most common forms of energy one of the most common forms of energy,the vibration energy takes advantage of energy harvesting technology to replace battery.And it became a new research hots pot.The main application of this technology is to supply energy for wireless sensor networks and miniaturized electronic devices.Although the most widely studied is the piezoelectric vibration transducer,but the traditional piezoelectric vibration energy transducer is still faced with a problem of a frequency response bandwidth narrow and low energy conversion efficiency.In order to solve the technical problem,the research group proposed the design thought of piezoelectric vibration energy transducer based miniature fractal structure,effectively broadening the energy harvesting bandwidth.On this basis,this paper further applies the fractal structure to PZT piezoelectric ceramics to improve the output voltage of the fractal vibration transducer.In this thesis,a fractal piezoelectric vibrator with two different levels of unit structure was designed.The self-similarity feature of the fractal structure resulted in two resonance frequencies,which can efficiently collect the vibration energy in a wide frequency range and increase the bandwidth of the piezoelectric transducer.And using the finite element software of ANSYS to build the model of piezoelectric vibrator and simulated by finite element method.Static and modal harmonic response analysis is carried out to verify the frequency response characteristics of the fractal piezoelectric vibrator.A piezoelectric vibration energy transducer with fractal structure was made in this paper.PZT piezoelectric ceramic with metal substrate was chosen as the piezoelectric material,and the fiber laser micro-machining equipment was used to cut the piezoelectric ceramic accurately,the designed fractal oscillator structure was processed,using the plexiglass to do the encapsulation protection,and it was finally manufactured with the piezoelectric vibration transducer.Fractal piezoelectric ceramic vibrate transducer was put to do the test of vibration acceleration and output voltage,periodic sweep experiment,vibration frequency and output voltage of vibrating source and output power of transducer under different loads.The experimental results show that the fractal piezoelectric vibration transducer has two resonance frequency points in low frequency environment,when the vibration acceleration of the source is 1.3g,the maximum output voltage is4.8V,the optimal load is 25K?,and the maximum output power is 0.24 mW.Therefore,theapplication of fractal structure to piezoelectric ceramics can further increase the output voltage on the basis of broadening the frequency response width.This paper analyzed the piezoelectric vibration transducer energy management interface circuit.Choosing the LTC3108 energy harvesting chip to manage the power collection of vibration transducer,introducing the working principle and function,and the fractal structure piezoelectric ceramic vibration transducer in this paper can output stable voltage by this chip according to the experimental verification.