Piezoelectric Generators for Vibrational Energy Harvesting

In past times, energy harvesting used piezoelectric materials was very popular for new research. The devices shapes sizes and dimensions was tested, but was difficult to match power measurement as a device fabrication and other method which vary from paper to paper. In an standard comparison by changing the parameters , the dependence of on device dimension has been investigated. The devices like MEMS scale have been measured little work has been using aluminium nitride. (PZT). The project shows and utilises ain due to its ease in processing and potential on chip integration . By using at this at MEMS scale the advantage is that array of piezo generators can be placed on the same die. With the use of ain a large goal of integrated power harvesting chips become achievable. The theoretical result of its scaling shows that power output and even power per unit volume will be decrease with scaling. This shows that the generator takes up the almost same area as other small generators would produce a noticeably a large power output. From the conclusion the result of this experiment were not most favourable. The problem in measuring the electrical response of the device lie beam shows the design involved with energy harvesting on a small scale. Piezoelectric generators rely on resonance to produce useful quantity , and power output is very sensitive to the frequency of the type of vibration applied. Although this type of generators are useful if targeted to specific application if the frequency of natural vibration is known. A more versatile approach could use other design to decrease the frequency sensitivity. Broad band design used either non resonant or self tuning structures could be able to harvest energy more easily in changing environment. keywords: PZT, Energy harvestors.