Two Dimensional, Multimodal, Low Fre-Quency Vibration Energy Harvester

In order to change the limitation of the traditional energy harvesters’ working on single directionincoming energy, broaden the frequency range of the energy harvester, increase the energy harvestingpower, this paper puts forward a new two-dimensional, multimodal, low-frequency vibration energyharvester, which is consist of a spiral shape substrate and a piece of piezoelectric ceramic paste on thesubstrate.Firstly, the principle of energy harvester was introduced, which comprise the piezoelectric effectof the piezoelectric materials, piezoelectric equations, piezoelectric constants and the commonly usedpiezoelectric materials.Secondly, the cantilever vibration energy harvester and its theoretical analysis was introduced.On the basis of the cantilever vibration energy harvester, the two-dimensional, multimodal,low-frequency vibration energy harvester which consists of a spiral shaped beam was proposed.Then, the harvester was simulated by the finite element analysis software ABAQUS, mainly forthe modal analysis and dynamic analysis. In order to get the influence of structural dimensions tonatural frequencies, python language was used to write the script files which are able to call thesoftware ABAQUS to do the recyclable modal analysis.Finally, the experimental platform was built to investigate the performance of the harvester. Themain contents of the experimental section include: performance comparison test between piezoelectricmaterial PVDF and PZT; the exploration of the location and number of the piezoelectric ceramics; theinfluence of the structure dimensions on the PZT open circuit voltage; the output power of the energyharvester.Experimental results show that, the harvester is not only able to collect energy from vibrationsalong two different directions in the X-Y plane, but also is a broadband multimodal energy harvester,which has many modals in frequency range of1Hz to100Hz. The maximum output power is0.259mW, which is really high. When the excitation frequency is21.2Hz, the output power is0.128mW, which prove a better performance of the energy harvester at low frequency.