Analytical modeling and validation of multi-mode piezoelectric energy harvester

2019 ◽  
Vol 124 ◽  
pp. 613-631 ◽  
Author(s):  
Xiangyang Li ◽  
Deepesh Upadrashta ◽  
Kaiping Yu ◽  
Yaowen Yang
Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 908 ◽  
Author(s):  
Sofiane Bouhedma ◽  
Yuhang Zheng ◽  
Dennis Hohlfeld

In this paper, we present a concept, simulation and characterization results of a dual-frequency piezoelectric energy harvester with magnetic frequency tuning capabilities. We demonstrate that the frequency-agile multi-mode capability enables the device to harvest on a wider range of operating frequencies than classical vibration harvesters.


2012 ◽  
Vol 1397 ◽  
Author(s):  
Seon-Bae Kim ◽  
Jung-Hyun Park ◽  
Seung-Hyun Kim ◽  
Hosang Ahn ◽  
H. Clyde Wikle ◽  
...  

ABSTRACTA transverse (d33) mode piezoelectric cantilever was fabricated for energy harvesting. Various dimensions of interdigital electrodes (IDE) were deposited on a piezoelectric layer to examine the effects of electrode design on the performance of energy harvesters. Modeling was performed to calculate the output power of the devices. The estimation was based on Roundy’s analytical modeling derived for a d31 mode piezoelectric energy harvester (PEH). In order to apply the Roundy’s model to d33 mode PEH, the IDE configuration was converted to the area of top and bottom electrodes (TBE). The power conversion in d33 mode PEH was commonly estimated by the product of piezoelectric layer’s thickness and finger electrode’s length. In addition, the spacing between fingers was regarded as gap between top and bottom electrodes. However, the output power in a transverse mode PEH increases continuously with the increase of finger spacing, which does not correspond to experimental results. In this research, the dimension of IDE was converted to that of TBE using conformal mapping, and variation of power of PEH was remodeled. The modified model suggests that the maximum power in a transverse mode PEH is obtained when the finger spacing is identical with effective finger spacing. The output power then decreases when finger spacing is larger than effective finger spacing. The decrease of efficiency may result from insufficient degree of poling and increased charged defect with increasing finger spacing.


Author(s):  
Sihong Zhao ◽  
Alper Erturk

Vibration-based energy harvesting has been heavily researched over the last decade with a primary focus on resonant excitation. However, ambient vibrational energy often has broader frequency content than a single harmonic, and in many cases it is entirely stochastic. As compared to the literature of deterministic energy harvesting, very few authors presented modeling approaches for energy harvesting from broadband random vibrations. These efforts have combined the input statistical information with the single-degree-of-freedom (SDOF) dynamics of the energy harvester to express the statistical electromechanical response characteristics. In most cases, the motion input (base acceleration) is assumed to be ideal white noise. White noise has a flat power spectral density (PSD) that might in fact excite higher vibration modes of an electroelastic energy harvester. In particular, piezoelectric energy harvesters constitute such continuous electroelastic systems with more than one vibration mode. This paper presents modeling and simulations of piezoelectric energy harvesting from broadband random vibrations based on distributed-parameter electroelastic solution. For white noise–type base acceleration of a given PSD level, first the general solution of the distributed-parameter problem is given. Closed-form representations are extracted for the single-mode case and these are analogous to the SDOF equations reported in the literature of energy harvesting. It is reported that the single-mode predictions might result in significant mismatch as compared to multi-mode predictions. Using the electroelastic solution, soft and hard piezoelectric power generators are compared under broadband random excitation. Shunt damping effect of power generation on the stochastic vibration response under broadband random excitation is also reported.


Author(s):  
Wanlu Zhou ◽  
Gopinath Reddy Penamalli ◽  
Lei Zuo

A novel piezoelectric energy harvester with multi-mode dynamic magnifier is proposed and investigated in this paper, which is capable of significantly increasing the bandwidth and the energy harvested from the ambient vibration. The design comprises of an multi-mode intermediate beam with a tip mass, called “dynamic magnifier”, and an “energy harvesting beam with a tip mass. The piezoelectric film is adhered to the harvesting beam to harvest the vibration energy. By properly designing the parameters, such as the length, width and thickness of the two beams and the weight of the two tip masses, we can virtually magnify the motion in all the resonance frequencies of the energy harvesting beam, in a similar way as designing a new beam-type tuned mass damper (TMD) to damp the resonance frequencies of all the modes of the primary beam. Theoretical analysis, finite element simulation, and the experiment study are carried out. The results show that voltage produced by the harvesting beam is amplified for efficient energy harvesting over a broader frequency range, while the peaks of the first three modes of the primary beam can be effectively mitigated simultaneously. The experiment demonstrates 25.5 times more energy harvesting capacity than the conventional cantilever type harvester in broadband frequency 3–300Hz, and over 1000 times more energy close to the first three resonances of harvesting beam.


Author(s):  
M. H. Ansari ◽  
M. Amin Karami

A fan-folded piezoelectric energy harvester is designed to generate electricity using heartbeat vibrations. This energy harvester consists of several bimorph beams stacked on top of each other making a fan-folded shape. Each beam has a brass substrate and two piezoelectric patches attached on both sides of it. These beams are connected to each other by rigid beams. One end of the device is clamped to the wall and the other end is free to vibrate. A tip mass is placed at the free end to enhance the output power of the device and reduce the natural frequency of the system. High natural frequency is one major concern about the microscaled energy harvesters. The size for this energy harvester is 1 cm by 1 cm by 1 cm, which makes the natural frequency very high. By utilizing the fan-folded geometry and adding tip mass and link mass to the configuration, this natural frequency is reduced to the desired range. The generated electricity can be used to power up a pacemaker. If enough electricity is generated, the pacemaker operates without having a battery and the patient does not need to have a surgery every seven to ten years to have the battery replaced. The power needed for a pacemaker to operate is about 1 microwatt. In this paper, the natural frequencies and mode shapes of fan-folded energy harvesters with added tip mass and link mass are analytically derived. The electro-mechanical coupling has been included in the model and the expression for the multi-mode power frequency response function is calculated.


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