Design And Fabrication Of Miniature Broadband Vibration Energy Harvesting Device Based On Fractal

With the rapid development of wireless sensor networks, research on how to power WSN nodeshas become a new hotspot. As the traditional way of power supply limited and the high cost of thebattery, it is being replaced by a new type of self-powered electronic devices.Vibration transducer is a generating device, which utilizes piezoelectric effect to scavengeambient environment energy. While, this transducer based on the cantilever structure meets manychallenges, such as higher quality factor, narrow band response and low energy conversionefficiency. For those challenges, this paper discusses the fractal structure and proposes a designmethod of broadband piezoelectric energy harvesting structure based on fractal structure. Suchfractal structure has a certain bandwidth and high space utilization rate. It’s easy to micromachining.According to this idea, a structure design based on Peano fractal curve is adopted. And, thefrequency distribution of the structure is discussed. And the suitable structure is obtained byoptimizing the structure parameters which is matched with the specific environment frequency.PVDF is chosed as the piezoelectric material in this paper, for its high piezoelectric coefficient.Based on the fractal structure design, a prototype size of50mm*50mm is made and packaged.Experimental data confirms the energy harvesting device with wide bandwidth of the resonantresponse. Meanwhile, ambient energy is obtained by the energy harvesting device effectively.