Research On Miniature Broadband Vibration Transducer With The Fractal Structure

In recent years, energy collection technology is becoming more and more important, among this,application of wireless sensor node power supply technology is the most important. With the rapiddevelopment of wireless sensor network, one of the hot spot of current research is that, using energyharvesting technology electronic devices of all kinds of work environment energy into electricity, soas to realize the self-energized of device. Currently the most widely used is based on the cantileverbeam structure of piezoelectric vibration energy transducers, but this structure exists a frequencyresponse bandwidth narrow and low energy conversion efficiency.In order to solve the above problems, proposed the design thought of broadband vibrationtransducer based miniature fractal structure in this paper. Fractal structure has the characteristics ofself-similarity and high space utilization, making it has more natural frequency points. At the sametime, there are many different types of cantilever beam structures in fractal structure, so it canproduce in a wider frequency range.According to this thought to design a piezoelectric vibration transducer based on the peanofractal structure, the use of cantilever structure theory to analyze the frequency characteristics of thebasic unit of fractal structure, Study the effects of the fractal structure parameters on frequencydistribution characteristics. Based on peano fractal structure model, plotted the frequency andfrequency number diagram. The results show that the fractal structure of bandwidth range20~600Hz, theoretically verified the structure can extend the bandwidth。And using the finite elementsoftware of COMSOL Multiphysics to build the model of the internal cantilever structure and theentire fractal structure verify the frequency characteristics of peano fractal structure.Finally, this paper presents experimental analysis. Experimental data confirms the energyharvesting device with wide bandwidth of the resonant response. Meanwhile, ambient energy isobtained by the energy harvesting device effectively.