A periodic folded piezoelectric beam for efficient vibration energy harvesting

Periodic piezoelectric beams have been used for broadband vibration energy harvesting in recent years. In this paper, a periodic folded piezoelectric beam (PFPB) is introduced. The PFPB has special features that distinguish it from other periodic piezoelectric beams. The Adomian decomposition method (ADM) is used to calculate the first two band gaps and twelve natural frequencies of the PFPB. Results show that this periodic beam has wide band gaps at low frequency ranges and the band gaps are close to each other. Results also show that the PFPB can efficiently generate voltage from the localized vibration energy over the band gaps. The natural frequencies of the PFPB are close to each other and most of them are out of the band gaps. Therefore, the PFPB can also generate the maximum voltage over a relatively wide frequency range out of the band gaps. In order to show these features better, the voltage output of the PFPB over a wide frequency range is calculated using the ANSYS software and compared with that of a conventional piezoelectric energy harvester. The ANSYS is also used to validate the analytical results and good agreement is found.