A Multi-Mode Broadband Vibration Energy Harvester Composed of Symmetrically Distributed U-Shaped Cantilever Beams

Abstract

Using the piezoelectric effect to harvest energy from surrounding vibrations is a promising alternative solution for powering small electronic devices such as wireless sensors and portable devices. A conventional piezoelectric energy harvester (PEH) can only efficiently collect energy within a small range around the resonance frequency. To realize broadband vibration energy harvesting, the idea of multiple-degrees-of-freedom (DOF) PEH to realize multiple resonant frequencies within a certain range has been recently proposed and some preliminary research has validated its feasibility. Therefore, this paper proposed a multi-DOF wideband PEH based on the frequency interval shortening mechanism to realize five resonance frequencies close enough to each other. The PEH consists of five tip masses, two U-shaped cantilever beams and a straight beam, and tuning of the resonance frequencies is realized by specific parameter design. The electrical characteristics of the PEH are analyzed by simulation and experiment, validating that the PEH can effectively expand the operating bandwidth and collect vibration energy in the low frequency. Experimental results show that the PEH has five low-frequency resonant frequencies, which are 13, 15, 18, 21 and 24 Hz; under the action of 0.5 g acceleration, the maximum output power is 52.2, 49.4, 61.3, 39.2 and 32.1 μW, respectively. In view of the difference between the simulation and the experimental results, this paper conducted an error analysis and revealed that the material parameters and parasitic capacitance are important factors that affect the simulation results. Based on the analysis, the simulation is improved for better agreement with experiments.

A Novel Bird-Shape Broadband Piezoelectric Energy Harvester for Low Frequency Vibrations

“…The piezoelectric cantilever array is a typical multi-DOF system, and different resonant frequencies can be obtained by adjusting the size of the cantilever beam and the tip masses. Dai et al [ 33 ] proposed a multi-DOF wideband PEH consisting of five tip masses, two U-shaped cantilever beams, and a straight beam with five resonant frequencies [ 34 ], which can effectively enlarge the operating bandwidth and collect vibration energy in low frequencies [ 35 , 36 , 37 ]. Ding et al [ 38 ] proposed a variant power generator array using an arc-shaped piezoelectric cantilever beam array, which had a satisfactory output performance.…”

Parametric and Experimental Modeling of Axial-Type Piezoelectric Energy Generator with Active Base

“…The article [25] considered a broadband PEG with several degrees of freedom based on five resonant frequencies that were fairly close to each other. The PEG consisted of five end masses, two U-shaped cantilever beams and a straight beam.…”

Functionalization of Internal Resonance in Magnetically Coupled Resonators for Highly Efficient and Wideband Hybrid Vibration Energy Harvesting

“…The disadvantages of this technique are the complexity of the design and ensuring that the amount of power required to tune the frequency is substantially less than the amount being harvested. On the other hand, the multimodal method has been previously proposed [ 12 , 13 , 14 , 15 , 16 , 17 ]. Several authors developed harvesters with multiple degrees-of-freedom (DOFs) where the power can be scavenged across a wider bandwidth [ 18 , 19 ].…”