Study On Vibrational Power Harvesting From Environment Based On Piezoelectric Structures

With the continuous improvement of MEMS technology in recent years, wireless sensornetwork node and a variety of portable microelectronic products more widely. Today, a variety ofMEMS power batteries, but with the node size is reduced and the number of rapid increase will bevery difficult to replace a lot of battery power technology research and sustainable use ofminiaturization has become urgent solution Key technical issues. In the wild, the vibration cancontinue to access to the kind of energy. The piezoelectric transducer can provide plenty of powerMEMS, has been widely used in the absence of the battery.The piezoelectric transducer can be collected to the energy and vibration frequency, amplitude,geometry, circuit load related. Among them, the vibration frequency is a crucial factor. When externalvibration to model the baseband resonance frequency, amplitude, voltage and power can be obtainedpeak. Therefore, the structural design of the vibration energy harvesting device involved in theapplication environment is closely related to, the application must be based on the vibration spectrumcharacteristics. Now the main way to reduce the resonant frequency of the beam length is to extendthe length of the beam and at the end to add mass, but the extension of MEMS applications is clearlyunreasonable, there is not enough space to add the mass effect is very small. In this way, thetransducer conversion efficiency will be much lower. In this paper, for this problem a new geometricstructure of a way to effectively reduce the cantilever resonance frequency and without a significantincrease in cantilever length. Made a theoretical analysis, the purpose is related to size parameters inorder to study the role of this cantilever structure. And prove it in the field of MEMS can also be closeto resonance, subsequently carried out using ANSYS software simulation. Analyzed for the sizeparameters of the piezoelectric voltage output and the resonant frequency, the simulation analysis ofthe optimal back-shaped structure.Then it made improvements to some of the problems common for today’s conditioning circuit.An adaptive piezoelectric transducer circuit has been improved, especially in the low-powerapplications, this new circuit will have a wide range of applications. Finally, an energy managementsystem, it is a storage structure used in conjunction with super capacitors and lithium batteries.