scholarly journals Fabrication and Electric Properties of Piezoelectric Cantilever Energy Harvesters Driven in 3-3 Vibration Mode

2017 ◽  
Vol 30 (5) ◽  
pp. 263-269 ◽  
Author(s):  
Min-seon Lee ◽  
Chang Il Kim ◽  
Ji-sun Yun ◽  
Woon-ik Park ◽  
Youn-woo Hong ◽  
...  
Keyword(s):  
Vibration Mode ◽  
Electric Properties ◽  
Energy Harvesters ◽  
Piezoelectric Cantilever

Experimental Study of a Self-Excited Piezoelectric Energy Harvester

2010 ◽  
Author(s):  
Hu¨seyin Dog˘us¸ Akaydın ◽  
Niell Elvin ◽  
Yiannis Andreopoulos
Keyword(s):  
Electrical Power ◽  
Natural Mode ◽  
Structural Vibrations ◽  
Energy Harvesters ◽  
Flow Energy ◽  
Piezoelectric Energy ◽  
Voltage Output ◽  
Aerodynamic Properties ◽  
Piezoelectric Cantilever ◽  
Measured Strain

In the present experimental work, we explore the possibility of using piezoelectric based fluid flow energy harvesters. These harvesters are self-excited and self-sustained in the sense that they can be used in steady uniform flows. The configuration consists of a piezoelectric cantilever beam with a cylindrical tip body which promotes sustainable, aero-elastic structural vibrations induced by vortex shedding and galloping. The structural and aerodynamic properties of the harvester alter the vibration amplitude and frequency of the piezoelectric beam and thus its electrical output. This paper presents results of energy-harvesting tests with one configuration of such a self-excited piezoelectric harvester using a PZT bimorph. In addition to the electrical voltage output, the strain on the surface of beam close to its clamped tip was also measured The measured strain and voltage output were perfectly correlated in the frequency range containing the first natural mode of vibration of the system. It was observed that about 0.24 mW of electrical power can be attained with this harvester in a uniform flow of 28 m/s.

A Smart Device for Harnessing Energy From Aerodynamic Flow Fields

2009 ◽  
Author(s):  
Daniel St. Clair ◽  
Christopher Stabler ◽  
Mohammed F. Daqaq ◽  
Jian Luo ◽  
Gang Li
Keyword(s):  
Wind Energy ◽  
Cantilever Beam ◽  
Flow Rate ◽  
Excitation Frequency ◽  
Volumetric Flow Rate ◽  
Smart Device ◽  
Electric Load ◽  
Energy Harvesters ◽  
Air Chamber ◽  
Piezoelectric Cantilever

In this work, inspired by music playing harmonicas, we conduct a conceptual investigation of a coupled aero-electromechanical system for wind energy harvesting. The system consists of a piezoelectric cantilever unimorph structure embedded within an air chamber to mimic the vibration of the reeds in a harmonica when subjected to air flow. In principle, when wind blows into the air chamber, the air pressure in the chamber increases and bends the cantilever beam opening an air path between the chamber and the environment. When the volumetric flow rate of air past the cantilever is large enough, the energy pumped into the structure via the nonlinear pressure forces offset the intrinsic damping in the system setting the beam into self-sustained limit-cycle oscillations. These oscillations induce a periodic strain in the piezoelectric layer which produces a voltage difference that can be channeled into an electric load. Unlike traditional vibratory energy harvesters where the excitation frequency needs to match the resonant frequency of the device for efficient energy extraction, the nonlinearly coupled aero-elasto dynamics of this device guarantees autonomous vibration of the cantilever beam near its natural frequency as long as the volumetric flow rate is larger than a certain threshold. Experimental results are presented to demonstrate the ability of this device to harvest wind energy under normal wind conditions.

Flow Energy Harvesters With a Nonlinear Restoring Force

2014 ◽  
Author(s):  
Ali H. Alhadidi ◽  
Amin Bibo ◽  
Mohammed F. Daqaq
Keyword(s):  
Bluff Body ◽  
Energy Harvester ◽  
Restoring Force ◽  
Energy Harvesters ◽  
Flow Energy ◽  
Nonlinear Restoring Force ◽  
Aerodynamic Loading ◽  
Lumped Parameter ◽  
Piezoelectric Cantilever ◽  
Different Shapes

This ppppaper examines the performance of a galloping energy harvester possessing a nonlinear restoring force. To achieve this goal, a flow energy harvester consisting of a piezoelectric cantilever beam augmented with a square-sectioned bluff body at the free end is considered. Two magnets located near the tip of the bluff body are used to introduce the nonlinearity which strength and nature can be altered by changing the distance between the magnets. A lumped-parameter aero-electromechanical model adopting the quasi-steady assumption for aerodynamic loading is presented and utilized to numerically simulate the harvester’s response. Wind tunnel tests are also performed to validate the numerical simulations by conducting upward and downward wind velocity sweeps. Results comparing the relative performance of several harvesters with potential functions of different shapes demonstrate that a mono-stable potential function with a hardening restoring force can outperform all other configurations.

Fabrication and analytical modeling of transverse mode piezoelectric energy harvesters

2012 ◽  
Vol 1397 ◽  
Author(s):  
Seon-Bae Kim ◽  
Jung-Hyun Park ◽  
Seung-Hyun Kim ◽  
Hosang Ahn ◽  
H. Clyde Wikle ◽  
...  
Keyword(s):  
Output Power ◽  
Analytical Modeling ◽  
Energy Harvester ◽  
Power Conversion ◽  
Transverse Mode ◽  
Modified Model ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Interdigital Electrodes ◽  
Piezoelectric Cantilever

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.

Parametric analysis of multilayered unimorph piezoelectric vibration energy harvesters

2015 ◽  
Vol 23 (15) ◽  
pp. 2538-2553 ◽  
Author(s):  
Ahmed Jemai ◽  
Fehmi Najar ◽  
Moez Chafra
Keyword(s):  
Energy Harvester ◽  
Electrical Power ◽  
Closed Form Solution ◽  
Beam Theory ◽  
Load Resistance ◽  
Form Solution ◽  
Energy Harvesters ◽  
Piezoelectric Energy ◽  
Piezoelectric Cantilever ◽  
Piezoelectric Layers

The use of a multilayer piezoelectric cantilever beam for vibration-based energy harvesting applications has been investigated as an effective technique to increase the harvested electrical power. It has been shown that the multilayered energy harvester performance is very sensitive to the number of layers and their electrical connection due to impedance variations. The objective of this work is to suggest a comprehensive mathematical model of multilayered unimorph piezoelectric energy harvester allowing analytical solution for the harvested voltage and electrical power. The model is used to deeply investigate the influence of different parameters on the harvested power. A distributed-parameter model of the harvester using the Euler–Bernoulli beam theory and Hamilton's principle is derived. Gauss's law is used to derive the electrical equations for parallel and series connections. A closed-form solution is proposed based on the Galerkin procedure and the obtained results are validated with a finite element 3D model. A parametric study is performed to ascertain the influence of the load resistance, the thickness ratio, the number of piezoelectric layers on the tip displacement and the electrical harvested power. It is shown that this model can be easily used to adjust the geometrical and electrical parameters of the energy harvester in order to improve the system's performances. In addition, it is proven that if one of the system's parameter is not correctly tuned, the harvested power can decrease by several orders of magnitude.

Exploiting Bi-Stability to Enhance Energy Capture From Turbulent Flows

2015 ◽  
Author(s):  
Ali H. Alhadidi ◽  
Mohammed F. Daqaq
Keyword(s):  
Wind Tunnel ◽  
Turbulent Flows ◽  
Output Power ◽  
Turbulence Intensity ◽  
Bluff Body ◽  
Reynolds Numbers ◽  
Restoring Force ◽  
Energy Capture ◽  
Energy Harvesters ◽  
Piezoelectric Cantilever

This paper investigates utilizing a nonlinear (bi-stable) restoring force to enhance the transduction of galloping energy harvesters in turbulent flows. To that end, a harvester consisting of a piezoelectric cantilever beam augmented with a square-sectioned bluff body at the free end is considered. Two repulsive magnets located at the tip of the beam are used to introduce the bi-stable restoring force. Turbulence is generated in a wind tunnel using static-grid structures located in the upstream of the bluff body. Three different mesh screens with square bars are designed with different bar and mesh widths to control the Reynolds numbers and associated turbulence intensity. A series of wind tunnel tests are then used to experimentally investigate the response of the harvester with and without the tip magnets. Results demonstrate that the bi-stable restoring force can be used to improve the output power of the harvester for sufficiently large turbulence intensities.

Utilizing Bi-Stability to Improve the Performance of Wake-Galloping Energy Harvesters in Unsteady Flow

2016 ◽  
Author(s):  
Ali H. Alhadidi ◽  
Mohammed F. Daqaq ◽  
Hamid Abderrahmane
Keyword(s):  
Wind Tunnel ◽  
Unsteady Flow ◽  
Output Power ◽  
Bluff Body ◽  
Unsteady Flows ◽  
Reynolds Numbers ◽  
Flow Conditions ◽  
Restoring Force ◽  
Energy Harvesters ◽  
Piezoelectric Cantilever

This paper investigates exploiting a bi-stable restoring force to enhance the transduction of wake-galloping energy harvesters in unsteady flows. To that end, a harvester consisting of a piezoelectric cantilever beam augmented with a square-sectioned bluff body at the free end is considered. Two repulsive magnets located at the tip of the beam are used to introduce the bi-stable restoring force. Unsteadiness is generated in a wind tunnel using static-grid structures located in the upstream of the bluff body. Three different mesh screens with square bars are designed with different bar and mesh widths to control the Reynolds numbers and associated unsteadiness. A series of wind tunnel tests are then used to experimentally investigate the response of the harvester with and without the tip magnets. Results demonstrate that the bi-stable restoring force can be used to improve the output power of the harvester under unsteady flow conditions.

Exploiting the Subharmonic Parametric Resonance of a Bi-Stable Beam for Energy Harvesting

2017 ◽  
Author(s):  
Samir A. Emam ◽  
Meghashyam Panyam ◽  
Mohammed F. Daqaq
Keyword(s):  
Electromechanical Coupling ◽  
Vibration Mode ◽  
Fiber Composite ◽  
Excitation Frequency ◽  
Energy Harvesters ◽  
Buckled Beam ◽  
Transverse Vibrations ◽  
Stable Equilibria ◽  
Theoretical Results ◽  
Good Agreement

We investigate the potential of harvesting vibration energy via a bi-stable beam subjected to subharmonic parametric excitations. The vibrating structure is a buckled beam with two stable equilibria separated by a potential barrier. The beam is subjected to a superposition of a static axial load beyond its critical buckling load and a harmonic axial excitation which frequency is around twice the frequency of the first vibration mode. A micro-fiber composite (MFC) is attached to one side of the beam to convert the strain energy resulting from the beams oscillation into electricity. The study considers two regimes of excitations: an amplitude sweep and a frequency sweep. In the first regime, the amplitude of excitation is varied while the excitation frequency is tuned at twice the natural frequency of the first vibration mode. In the second regime, the excitation frequency is swept forward and backward around the subharmonic resonant frequency while the amplitude of excitation is kept constant. A theoretical model which governs the electromechanical coupling of the transverse vibrations of the beam and the output voltage is used to monitor the response as the excitation parameters are changed. An experimental setup is built and a series of tests is performed. The theoretical results are in good agreement with their experimental counterparts. The experiment also shows that this type of bi-stable energy harvesters exhibits a broadband frequency response as compared to the classical linear harvesters.

Reduced-Order Modeling of Energy Harvesters

2009 ◽  
Author(s):  
Thiago Seuaciuc-Oso´rio ◽  
Mohammed F. Daqaq
Keyword(s):  
Output Power ◽  
Cantilever Beam ◽  
Electromechanical Coupling ◽  
Single Mode ◽  
Exact Expression ◽  
Reduced Order ◽  
Energy Harvesters ◽  
Piezoelectric Cantilever ◽  
Design Values ◽  
Ritz Procedure

This work addresses the accuracy and convergence of reduced-order models (ROMs) of energy harvesters. Two types of energy harvesters are considered, a magnetostrictive rod in axial vibrations and a piezoelectric cantilever beam in traverse oscillations. The partial differential equations (PDEs) and associated boundary conditions governing the motion of these harvesters are obtained. The eigenvalue problem is then solved for the exact eigenvalues and modeshapes. Furthermore, an exact expression for the steady-sate output power is attained by direct solution of the PDEs. Subsequently, the results are compared to a ROM attained following the Rayleigh-Ritz procedure. It is observed that the eigenvalues and output power near the first resonance frequency are more accurate and has a much faster convergence to the exact solution for the piezoelectric cantilever beam. In addition, it is shown that the convergence is governed by two dimensionless constants, one that is related to the electromechanical coupling and the other to the ratio between the time constant of the mechanical oscillator and the harvesting circuit. Using these results, conclusions are drawn with regards to the design values for which the common single-mode ROM is accurate.

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