High Efficiency Piezoelectric Energy Harvester with Synchronized Switching Interface Circuit

This paper presents a new vibration driven energy harvesting device with an additional synchronized switching interface for optimizing the power transfer from the energy harvester to a storage element. The energy transducer consists of a piezoelectric energy harvester, which is designed to achieve a uniform stress distribution on the whole generator structure. A novel interface circuitry, based on the initial energy injection described by Lallart et. all. [1], is added to the system. It enables a harvesting process that is almost independent of the load and allows an almost ideal energy storage process. The results of parameter studies for an optimal generator design as well as first measurement results obtained with the direct initial energy injection circuitry are presented and discussed in the presentation. The results show that an efficiency benefit by a factor of 3, compared to standard devices can be achieved by the presented device.