Finite Element Analysis and Experiment on a Piezoelectric Harvester with Multiple Cantilevers (original) (raw)
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Development of Vibration Piezoelectric Harvesters by the Optimum Design of Cantilever Structures
Nanogenerators [Working Title]
Piezoelectric energy harvesting is a way of converting waste mechanical energy into usable electrical form. The selection of mechanical devices for conversion of mechanical to electrical energy is a significant part of vibration energy harvesting. The articles provide designing and optimization of a cantilever piezoelectric energy harvester. At first, is the selection of best mechanical device for energy harvesting application. A cantilever without proof mass is then analyzed for the selection of substrate, and piezoelectric material also plays a key role in the performance of the device. Aluminum is selected as a substrate, while zinc oxide acts as the piezoelectric layer. Addition of proof mass reduces the resonant frequency of the device to about 51 Hz as compared to 900 Hz for an aluminum cantilever beam. An electromechanical study shows an active conversion of mechanical input energy to electrical output energy. Power frequency response functions of the resultant structure are able to generate 0.47 mW power having 6.8 μA current at 1 g input acceleration.
Investigation of Electrical Properties for Cantilever-Based Piezoelectric Energy Harvester
Advances in Science and Technology Research Journal
In the present era, the renewable sources of energy, e.g., piezoelectric materials are in great demand. They play a vital role in the field of micro-electromechanical systems, e.g., sensors and actuators. The cantilever-based piezoelectric energy harvesters are very popular because of their high performance and utilization. In this researchwork, an energy harvester model based on a cantilever beam with bimorph PZT-5A, having a substrate layer of structural steel, was presented. The proposed energy scavenging system, designed in COMSOL Multiphysics, was applied to analyze the electrical output as a function of excitation frequencies, load resistances and accelerations. Analytical modeling was employed to measure the output voltage and power under pre-defined conditions of acceleration and load resistance. Experimentation was also performed to determine the relationship between independent and output parameters. Energy harvester is capable of producing the maximum power of 1.16 mW at a resonant frequency of 71 Hz under 1g acceleration, having load resistance of 12 kΩ. It was observed that acceleration and output power are directly proportional to each other. Moreover, the investigation conveys that the experimental results are in good agreement with the numerical results. The maximum error obtained between the experimental and numerical investigation was found to equal 4.3%.
Analysis of angular position, dimension and material of a cantilever piezoelectric energy harvester
Ferroelectrics, 2018
The performance of an angular vibrating single piezoelectric cantilever beam energy harvester in a flexural mode was analyzed. In this research the approaches of theory, finite element, and experiment have been undertaken to study the effects of angular position, mechanical properties, and dimensions on the output power and resonance frequency of a piezoelectric cantilever beam. The phase shift is an important phenomenon observed in this system because of the angular position of the beam about its longitudinal axis. Frequency shift due to the angular position is usually observed in experiments. However, it has not been studied theoretically until now. The angular position not only affects the resonance frequency but also the amount of output power from the lead zirconate titanate ceramic bonded on it. Furthermore, beam and piezoelectric dimensions have a major effect on power output and resonance frequency. Another aspect considered in this research is the effect of materials on power and frequency which have been studied for aluminum, copper, and steel.
Micromachines, 2021
One of the most important challenges in the design of the piezoelectric energy harvester is its narrow bandwidth. Most of the input vibration sources are exposed to frequency variation during their operation. The piezoelectric energy harvester’s narrow bandwidth makes it difficult for the harvester to track the variations of the input vibration source frequency. Thus, the harvester’s output power and overall performance is expected to decline from the designed value. This current study aims to solve the problem of the piezoelectric energy harvester’s narrow bandwidth. The main objective is to achieve bandwidth broadening which is carried out by segmenting the piezoelectric material of the energy harvester into n segments; where n could be more than one. Three arrays with two, four, and six beams are shaped with two piezoelectric segments. The effect of changing the length of the piezoelectric material segment on the resonant frequency, output power, and bandwidth, as well as the fre...
Efficiency Enhancement of a Cantilever-Based Vibration Energy Harvester
Sensors, 2013
Extracting energy from ambient vibration to power wireless sensor nodes has been an attractive area of research, particularly in the automotive monitoring field. This article reports the design, analysis and testing of a vibration energy harvesting device based on a miniature asymmetric air-spaced cantilever. The developed design offers high power density, and delivers electric power that is sufficient to support most wireless sensor nodes for structural health monitoring (SHM) applications. The optimized design underwent three evolutionary steps, starting from a simple cantilever design, going through an air-spaced cantilever, and ending up with an optimized air-spaced geometry with boosted power density level. Finite Element Analysis (FEA) was used as an initial tool to compare the three geometries' stiffness (K), output open-circuit voltage (V ave), and average normal strain in the piezoelectric transducer (ε ave) that directly affect its output voltage. Experimental tests were also carried out in order to examine the energy harvesting level in each of the three designs. The experimental results show how to boost the power output level in a thin air-spaced cantilever beam for energy within the same space envelope. The developed thin air-spaced cantilever (8.37 cm 3), has a maximum power output of 2.05 mW (H = 29.29 μJ/cycle).
Sensors, 2015
This paper focuses on several aspects extending the dynamical efficiency of a cantilever beam vibrating in the third mode. A few ways of producing this mode stimulation, namely vibro-impact or forced excitation, as well as its application for energy harvesting devices are proposed. The paper presents numerical and experimental analyses of novel structural dynamics effects along with an optimal configuration of the cantilever beam. The peculiarities of a cantilever beam vibrating in the third mode are related to the significant increase of the level of deformations capable of extracting significant additional amounts of energy compared to the conventional harvester vibrating in the first mode. Two types of a piezoelectric vibrating energy harvester (PVEH) prototype are analysed in this paper: the first one without electrode segmentation, while the second is segmented using electrode segmentation at the strain nodes of the third vibration mode to achieve effective operation at the third resonant frequency. The results of this research revealed that the voltage generated by any segment of the segmented PVEH prototype excited at the third resonant frequency demonstrated a 3.4-4.8-fold increase in comparison with the
Investigation of Multifrequency Piezoelectric Energy Harvester
Shock and Vibration
This paper presents results of numerical and experimental investigations related to the piezoelectric energy harvester that operates at multifrequency mode. Employment of such operation principle provides an opportunity for obtaining frequency response characteristics of the harvester with several resonant frequencies and in this way increasing efficiency of the harvester at a wide spectrum of excitation frequencies. The proposed design of the energy harvester consists of five cantilevers which forms square type system. Cross sections of the cantilevers are modified by periodical cylindrical gaps in order to increase strain value and to obtain more uniform strain distribution along the cantilevers. Cantilevers are rigidly connected to each other and compose an indissoluble system. Square type harvester has seismic masses at every corner. These masses are placed under specific angle in order to reduce natural frequencies of the system and to create additional rotation moments in the ...
Vibration Energy Harvest for Low Frequency using Double- piezoelectric Cantilever Beam
MATEC Web of Conferences, 2020
This study introduces design methods of natural frequency for double-piezoelectric cantilever beams in order to absorb electricity from mechanical vibration. The natural frequencies of double cantilever beams are designed by quadratic equation such as 6.45 and 18.14 Hz. On the other hands, FEA is used to recheck the result. FEA simulation presents the natural frequencies such as 4.4614, 8.4793, 13.8020 and 25.1050 Hz. It works in low frequency and large bandwidth. The experimental results show the peak electric power at 5 and 22 Hz. The error may occur by stiffness of piezoelectric and effective of mounting position.
Energy Harvesting and Systems, 2014
A long-standing encumbrance in the design of low-frequency energy harvesters has been the need of substantial beam length and/or large tip mass values to reach the low resonance frequencies where significant energy can be harvested from the ambient vibration sources. This need of large length and tip mass may result in a device that is too large to be practical. The zigzag (meandering) beam structure has emerged as a solution to this problem. In this letter, we provide comparative analysis between the classical one-dimensional cantilever bimorph and the two-dimensional zigzag unimorph piezoelectric energy harvesters. The results demonstrate that depending upon the excitation frequency, the zigzag harvester is significantly better in terms of magnitude of natural frequency, harvested power, and power density, compared to the cantilever configuration. The dimensions were chosen for each design such that the zigzag structure would have 25.4 Â 25.4 mm 2 area, and the cantilever would have the same surface area. The zigzag prototype of 25.4 Â 25.4 mm 2 area was capable of generating 65 μW/cm 3 at 32 Hz when subjected to 0.1 G base acceleration.
2019
Piezoelectric cantilevers are mostly used for vibration energy harvesting. Changing the shape of the cantilevers could affect the generated output power and voltage. In this work, vibration energy harvesting via piezoelectric resonant unimorph cantilevers is considered. Moreover, a new design to obtain more wideband piezoelectric energy harvester is suggested. This study also provides a comprehensive analysis of the output voltage relationships and deducing an essential precise rule of thumb to calculate resonance frequency in cantilever-type unimorph piezoelectric energy harvesters using the Rayleigh-Ritz method. The analytical formula is then analyzed and verified by experiment on a fabricated prototype. The analytical data was found in an agreement with the experimental results. An important finding is that among all the unimorph tapered cantilever beams with uniform thickness, the triangular cantilever, can lead to highest resonance frequency and by increasing the ratio of the trapezoidal bases, the resonance frequency decreases. It is concluded that the shape can have a significant effect on the output voltage and therefore maximum output power density. Some triangular cantilever energy harvesters can arrange in pizza form using cantilever arrays. This arrangement decreases the occupied space and can lead to increasing the power density and also operating bandwidth.