Design considerations of MEMS based piezoelectric cantilever for harvesting energy

One of the challenges of miniature electronic system such as those work as a part of a wider wireless sensor system is to provide sustainable electrical power source to all the electronic components in a small enclosure of sensor node. However, as the size of the micro-power generator reduces, the physical limitations as well as the reduction of output power become the major concerns of the usefulness of a miniature energy harvester. In this paper, the design is taking into considerations of the mechanical as well as the electrical properties of an unimorph piezoelectric cantilever. These encompassed the natural frequency and the neutral axis of the structure. Resistive load was also being investigated for optimizing the electrical output power of the micro-generator. It was found that the issue of the maximum deflection of the cantilever is more prominent than the stress on the cantilever for a miniature device. The adjustment on the neutral axis as well as on matching with resistive load are also important in generating optimum electrical output power.