Theoretical modeling of longitudinal piezoelectric characteristic for cellular polymers

2021 ◽  
pp. 026248932110558
Author(s):  
Ikrame Najihi ◽  
Chouaib Ennawaoui ◽  
Abdelowahed Hajjaji ◽  
Yahia Boughaleb
Keyword(s):  
Energy Harvesting ◽  
Electrical Energy ◽  
Power Devices ◽  
Piezoelectric Polymers ◽  
Poly Ethylene ◽  
Difficult Challenge ◽  
Theoretical Results ◽  
Piezoelectric Performance ◽  
Piezoelectric Characteristic ◽  
Good Agreement

Efficient energy harvesting is a difficult challenge that consists in the development of systems allowing charging autonomous and low-power devices. In addition to traditional piezoelectric polymers, mono-crystals, and ceramics, cellular electrets offer consistent solutions by converting wasted vibration energy from the environment to usable electrical energy. This paper presents an electromechanical model to study the energy harvesting capability of cellular polymers. The theoretical study models the response of these materials to investigate the effect of different parameters on the piezoelectric coefficient d33, particularly. The model considers the percentage of porosity, surface charge density in each polymer–gas surface, the properties of the polymer matrix and the gas encapsulated in the pores, and the Young’s modulus of the porous film. For poly(ethylene-co-vinyl acetate), the results showed that the piezoelectric performance of the film declines with the increase of the film thickness. However, the variation of the d33 as a function of the percentage of porosity is exponential and can achieve 4.24 pC/N for a porosity of 80%. Compared to a previously published experiment, the theoretical results have proven a good agreement with only 3.3% error.

Analytical Electromechanical Model of Cantilevered Bi-Stable Composites for Broadband Energy Harvesting

2013 ◽  
Author(s):  
Andres F. Arrieta ◽  
Tommaso Delpero ◽  
Paolo Ermanni
Keyword(s):  
Energy Harvesting ◽  
Large Amplitude ◽  
Wide Band ◽  
Electrical Energy ◽  
Ambient Vibration ◽  
Mode Shapes ◽  
Rapid Reduction ◽  
Electromechanical Model ◽  
Response Characteristics ◽  
Good Agreement

Vibration based energy harvesting has received extensive attention in the engineering community for the past decade thanks to its potential for autonomous powering small electronic devices. For this purpose, linear electromechanical devices converting mechanical to useful electrical energy have been extensively investigated. Such systems operate optimally when excited close to or at resonance, however, for these lightly damped structures small variations in the ambient vibration frequency results in a rapid reduction of performance. The idea to use nonlinearity to obtain large amplitude response in a wider frequency range, has shown the potential for achieving so called broadband energy harvesting. An interesting type of nonlinear structures exhibiting the desired broadband response characteristics are bi-stable composites. The bi-stable nature of these composites allows for designing several ranges of wide band large amplitude oscillations, from which high power can be harvested. In this paper, an analytical electromechanical model of cantilevered piezoelectric bi-stable composites for broadband harvesting is presented. The model allows to calculate the modal characteristics, such as natural frequencies and mode shapes, providing a tool for the design of bi-stable composites as harvesting devices. The generalised coupling coefficient is used to select the positioning of piezoelectric elements on the composites for maximising the conversion energy. The modal response of a test specimen is obtained and compared to theoretical results showing good agreement, thus validating the model.

Piezoelectric Energy Harvesting for Powering Micro Electromechanical Systems (MEMS)

2015 ◽  
Vol 8 (1) ◽  
Author(s):  
A. Majeed
Keyword(s):  
Energy Harvesting ◽  
Low Power ◽  
Piezoelectric Materials ◽  
Electrical Energy ◽  
Piezoelectric Energy Harvesting ◽  
Wireless Technology ◽  
Power Devices ◽  
Piezoelectric Energy ◽  
Technical Innovations ◽  
Low Power Electronics

Recent advancements in wireless technology and low power electronics such as micro electrome-chanical systems (MEMS), have created a surge of technical innovations in the eld of energy har-vesting. Piezoelectric materials, which operate on vibrations surrounding the system have becomehighly useful in terms of energy harvesting. Piezoelectricity is the ability to transform mechanicalstrain energy, mostly vibrations, to electrical energy, which can be used to power devices. This paperwill focus on energy harvesting by piezoelectricity and how it can be incorporated into various lowpower devices and explain the ability of piezoelectric materials to function as self-charging devicesthat can continuously supply power to a device and will not require any battery for future processes.

scholarly journals Piezoelectric and Electromechanical Characteristics of Porous Poly(Ethylene-co-Vinyl Acetate) Copolymer Films for Smart Sensors and Mechanical Energy Harvesting Applications

2021 ◽  
Vol 4 (3) ◽  
pp. 57
Author(s):  
Chouaib Ennawaoui ◽  
Abdelowahed Hajjaji ◽  
Cédric Samuel ◽  
Erroumayssae Sabani ◽  
Abdelkader Rjafallah ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Vinyl Acetate ◽  
Polymer Films ◽  
Smart Materials ◽  
Mechanical Energy ◽  
Electrical Energy ◽  
Void Content ◽  
Piezoelectric Polymer ◽  
Poly Ethylene ◽  
Porosity Percentage

This paper investigates energy harvesting performances of porous piezoelectric polymer films to collect electrical energy from vibrations and power various sensors. The influence of void content on the elastic matrix, dielectric, electrical, and mechanical properties of porous piezoelectric polymer films produced from available commercial poly(ethylene-co-vinyl acetate) using an industrially applicable melt-state extrusion method (EVA) were examined and discussed. Electrical and mechanical characterization showed an increase in the harvested current and a decrease in Young’s modulus with the increasing ratio of voids. Thermal analysis revealed a decrease in piezoelectric constant of the porous materials. The authors present a mathematical model that is able to predict harvested current as a function of matrix characteristics, mechanical excitation and porosity percentage. The output current is directly proportional to the porosity percentage. The harvested power significantly increases with increasing strain or porosity, achieving a power value up to 0.23, 1.55, and 3.87 mW/m3 for three EVA compositions: EVA 0%, EVA 37% and EVA 65%, respectively. In conclusion, porous piezoelectric EVA films has great potential from an energy density viewpoint and could represent interesting candidates for energy harvesting applications. Our work contributes to the development of smart materials, with potential uses as innovative harvester systems of energy generated by different vibration sources such as roads, machines and oceans.

Investigating the Nonlinear Optical Response of Pepper Oil under Low Power Irradiation with Continuous Wave Visible Laser Beam

2020 ◽  
pp. 131-138
Keyword(s):  
Refractive Index ◽  
Nonlinear Refractive Index ◽  
Nonlinear Optical ◽  
Continuous Wave ◽  
Diffraction Integral ◽  
Visible Laser ◽  
Limiting Property ◽  
Kirchhoff Diffraction Integral ◽  
Theoretical Results ◽  
Good Agreement

The nonlinear optical properties of pepper oil are studied by diffraction ring patterns and Z-scan techniques with continuous wave beam from solid state laser at 473 nm wavelength. The nonlinear refractive index of the sample is calculated by both techniques. The sample show high nonlinear refractive index. Based on Fresnel-Kirchhoff diffraction integral, the far-field intensity distributions of ring patterns have been calculated. It is found that the experimental results are in good agreement with the theoretical results. Also the optical limiting property of pepper oil is reported. The results obtained in this study prove that the pepper oil has applications in nonlinear optical devices.

Synthesis and conformational investigation of β-turn forming tetra- and hexapeptides

1982 ◽  
Vol 47 (7) ◽  
pp. 1884-1892
Author(s):  
A. N. Abdel Rahman ◽  
S. Abdel Rahman
Keyword(s):  
Energy Transfer ◽  
Phase Method ◽  
Conformational Study ◽  
Poly Ethylene Glycol ◽  
High Solubility ◽  
Liquid Phase Method ◽  
Conformational Investigation ◽  
Transfer Method ◽  
Poly Ethylene ◽  
Good Agreement

Tetra- and hexapeptides containing Pro-Gly or Gly-Pro or Aib-Pro in their sequences were synthesized using the liquid-phase method. The high solubility of the poly(ethylene glycol) bound peptides in water and in organic solvents enables the application of the singlet-singlet energy transfer method for conformational investigation of these peptides. The conformational study in solid state by IR and in solution by CD were carried out in parallel to the energy transfer method. The qualitative results generated by IR and CD were found to be in good agreement with the quantitative end-to-end distances given by the energy transfer method.

scholarly journals Emerging Energy Harvesting Technology for Electro/Photo-Catalytic Water Splitting Application

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 142
Author(s):  
Jianfei Tang ◽  
Tianle Liu ◽  
Sijia Miao ◽  
Yuljae Cho
Keyword(s):  
Energy Harvesting ◽  
Water Splitting ◽  
Social Impact ◽  
Electrical Energy ◽  
Future Research ◽  
Daily Lives ◽  
Energy Applications ◽  
Sustainable Environment ◽  
Energy Technologies ◽  
Splitting System

In recent years, we have experienced extreme climate changes due to the global warming, continuously impacting and changing our daily lives. To build a sustainable environment and society, various energy technologies have been developed and introduced. Among them, energy harvesting, converting ambient environmental energy into electrical energy, has emerged as one of the promising technologies for a variety of energy applications. In particular, a photo (electro) catalytic water splitting system, coupled with emerging energy harvesting technology, has demonstrated high device performance, demonstrating its great social impact for the development of the new water splitting system. In this review article, we introduce and discuss in detail the emerging energy-harvesting technology for photo (electro) catalytic water splitting applications. The article includes fundamentals of photocatalytic and electrocatalytic water splitting and water splitting applications coupled with the emerging energy-harvesting technologies using piezoelectric, piezo-phototronic, pyroelectric, triboelectric, and photovoltaic effects. We comprehensively deal with different mechanisms in water splitting processes with respect to the energy harvesting processes and their effect on the water splitting systems. Lastly, new opportunities in energy harvesting-assisted water splitting are introduced together with future research directions that need to be investigated for further development of new types of water splitting systems.

Studies of local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) crystals

2021 ◽  
Vol 76 (4) ◽  
pp. 299-304
Author(s):  
Fu Chen ◽  
Jian-Rong Yang ◽  
Zi-Fa Zhou
Keyword(s):  
Crystal Field ◽  
Elongation Ratio ◽  
Paramagnetic Resonance ◽  
Local Structures ◽  
Epr Parameters ◽  
Structure Constants ◽  
Crystal Field Parameters ◽  
Electron Paramagnetic ◽  
Theoretical Results ◽  
Good Agreement

Abstract The electron paramagnetic resonance (EPR) parameters (g factor g i , and hyperfine structure constants A i , with i = x, y, z) and local structures for Cu2+ centers in M2Zn(SO4)2·6H2O (M = NH4 and Rb) are theoretically investigated using the high order perturbation formulas of these EPR parameters for a 3d 9 ion under orthorhombically elongated octahedra. In the calculations, contribution to these EPR parameters due to the admixture of d-orbitals in the ground state wave function of the Cu2+ ion are taken into account based on the cluster approach, and the required crystal-field parameters are estimated from the superposition model which enables correlation of the crystal-field parameters and hence the studied EPR parameters with the local structures of the Cu2+ centers. Based on the calculations, the Cu–H2O bonds are found to suffer the axial elongation ratio δ of about 3 and 2.9% along the z-axis, meanwhile, the planar bond lengths may experience variation ratio τ (≈3.8 and 1%) along x- and y-axis for Cu2+ center in (NH4)2Zn(SO4)2·6H2O and Rb2Zn(SO4)2·6H2O, respectively. The theoretical results show good agreement with the observed values.

On the Flow Fields of Inertial Impactors

1974 ◽  
Vol 96 (4) ◽  
pp. 394-400 ◽  
Author(s):  
V. A. Marple ◽  
B. Y. H. Liu ◽  
K. T. Whitby
Keyword(s):  
Flow Field ◽  
Stokes Equations ◽  
Relaxation Method ◽  
Water Model ◽  
Navier Stokes ◽  
Visualization Technique ◽  
Navier Stokes Equations ◽  
Theoretical Results ◽  
Plate Distance ◽  
Good Agreement

The flow field in an inertial impactor was studied experimentally with a water model by means of a flow visualization technique. The influence of such parameters as Reynolds number and jet-to-plate distance on the flow field was determined. The Navier-Stokes equations describing the laminar flow field in the impactor were solved numerically by means of a finite difference relaxation method. The theoretical results were found to be in good agreement with the empirical observations made with the water model.

Experimental Research of Energy Harvesting and Storage Based on Ferroelectric Materials

2012 ◽  
Vol 476-478 ◽  
pp. 1336-1340
Author(s):  
Kai Feng Li ◽  
Rong Liu ◽  
Lin Xiang Wang
Keyword(s):  
Energy Harvesting ◽  
Electromagnetic Waves ◽  
Vibrational Energy ◽  
Waste Heat ◽  
Mechanical Strain ◽  
Electrical Potential ◽  
Electrical Energy ◽  
Ferroelectric Materials ◽  
Energy Scavenging ◽  
And Storage

The concept of energy harvesting works towards developing self-powered devices that do not require replaceable power supplies. Energy scavenging devices are designed to capture the ambient energy surrounding the electronics and convert it into usable electrical energy. A number of sources of harvestable ambient energy exist, including waste heat, vibration, electromagnetic waves, wind, flowing water, and solar energy. While each of these sources of energy can be effectively used to power remote sensors, the structural and biological communities have placed an emphasis on scavenging vibrational energy with ferroelectric materials. Ferroelectric materials have a crystalline structure that provide a unique ability to convert an applied electrical potential into a mechanical strain or vice versa. Based on the properties of the material, this paper investigates the technique of power harvesting and storage.

Design of a Multifunctional Aircraft Skin With Energy Harvesting via Entropy Generation Minimization

Aerospace ◽  
2006 ◽  
Author(s):  
K. Ahlers ◽  
K. P. Hallinan ◽  
B. Sanders ◽  
R. McCarty
Keyword(s):  
Energy Harvesting ◽  
Entropy Generation ◽  
Waste Heat ◽  
Skin Layer ◽  
Skin Thickness ◽  
Power Devices ◽  
Volume Fractions ◽  
Entropy Generation Minimization ◽  
The Matrix ◽  
Aircraft Skin

The Entropy Generation Minimization (EGM) approach is applied to the design of a new integrated radar aircraft skin, which both meets requisite aircraft structural needs and provides a pathway for the waste heat from structurally integrated power devices. Thermoelectric (TE) devices, sandwiched between a heterogeneous skin layer and the radar devices for the purpose of harvesting waste heat rejected to the ambient, are considered in the analysis. A heterogeneous skin layer is designed using the EGM approach, which is then applied to the overall mission of the aircraft to determine the optimal skin thickness and volume fractions of the matrix and inclusions in the composite skin.

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