S Shaped Multimodal Piezoelectric Energy Harvester

Vibration based piezoelectric energy harvester have attracted a lot of interest due to its simple implementations and high energy density. However, if natural frequencies of the system do not correspond to an input vibration frequency, generated power decreases significantly. In this paper, a new broadband piezoelectric energy harvester that consist of three beams and seems like the alphabet S is introduced. The equations of motion are built. A modal analysis is conducted and the results show that the lowest three natural frequencies can be spaced so closely by changing the length, thickness, and tip mass of each beam.??? ????????? ???????????? ???????????????????????? ???????????? ????????????????????????(KEPEP)??? ????????? ?????? ????????? ????????? (Project No. 20142020103970