The long term aim of this project is to develop a miniature, self powered and wireless sensor. Energy harvesting provides attractive and exciting opportunities for powering low power micro and nano devices. Conventional energy sources (i.e.: batteries) will not be an impeding factor in designing and maintenance, they can be replaced by the „perpetual” MEMS generators. Pre-experiments have been made in the Hungarian Academy of Sciences Research Centre for Natural Sciences (Hungarian acronym: MTA TTK). The energy harvester will be based on piezoelectric effect and will be fabricated with MEMS technology.
Ambient vibrations will be converted into electrical power via the piezoelectric layer on the cantilever, which will drive the sensor circuit. Important note that the typical ambient frequency is around/below 100Hz thus the resonance frequency of the cantilevers should be tuned in this frequency domain. To achieve that, we have to find the ideal geometry for the structures first.
In this work simulations for the resonance frequency of the cantilevers will be presented, from the simplest to the more complex ones. Furthermore to conclude each simulation a silicon layout will be presented. These layouts are designed for the experiments to verify the simulation results.
In the final part I will present the fabrication technology and summarize the experiences from the process of each cantilever generation.