scholarly journals Constructive and Destructive Interplay Between Piezoelectricity and Flexoelectricity in Flexural Sensors and Actuators

2015 ◽  
Vol 82 (12) ◽  
Author(s):  
Amir Abdollahi ◽  
Irene Arias
Keyword(s):  
Electromechanical Coupling ◽  
Size Dependence ◽  
Piezoelectric Effect ◽  
Piezoelectric Materials ◽  
Piezoelectric Transducers ◽  
Ferroelectric Ceramics ◽  
Small Scale ◽  
Piezoelectric Bimorph ◽  
Sensors And Actuators ◽  
Strain Gradients

Flexoelectricity is an electromechanical effect coupling polarization to strain gradients. It fundamentally differs from piezoelectricity because of its size-dependence and symmetry. Flexoelectricity is generally perceived as a small effect noticeable only at the nanoscale. Since ferroelectric ceramics have a particularly high flexoelectric coefficient, however, it may play a significant role as piezoelectric transducers shrink to the submicrometer scale. We examine this issue with a continuum model self-consistently treating piezo- and flexoelectricity. We show that in piezoelectric device configurations that induce strain gradients and at small but technologically relevant scales, the electromechanical coupling may be dominated by flexoelectricity. More importantly, depending on the device design flexoelectricity may enhance or reduce the effective piezoelectric effect. Focusing on bimorph configurations, we show that configurations that are equivalent at large scales exhibit dramatically different behavior for thicknesses below 100 nm for typical piezoelectric materials. Our results suggest flexoelectric-aware designs for small-scale piezoelectric bimorph transducers.

Characterization of Piezoelectric Materials for Thermoacoustic Power Transduction

2008 ◽  
Author(s):  
A. Wekin ◽  
C. Richards ◽  
K. Matveev ◽  
M. Anderson
Keyword(s):  
Experimental Study ◽  
Piezoelectric Materials ◽  
Electrical Power ◽  
Power Production ◽  
Piezoelectric Transducers ◽  
Maximum Power ◽  
Small Scale ◽  
Thermoacoustic Engine ◽  
Thermoacoustic Engines

In this work an experimental study of the performance of piezoelectric transducers for power production from a small-scale thermoacoustic engine is presented. Four piezoelectric samples are identified and characterized. These samples are tested on a variable acoustic driver and electrical power produced is measured. Finally, the samples are tested on four experimental thermoacoustic engines to verify the results from the acoustic setup. The maximum power produced is 177 μW from a closed thermoacoustic engine coupled to a 15mm PZT disk.

Lead Free (Bi, Na)TiO3–BiAlO3 Ceramics for Piezoelectric Application

2020 ◽  
Vol 15 (4) ◽  
pp. 459-462
Author(s):  
Jae-Hoon Ji ◽  
Don-Jin Shin ◽  
Sang-Kwon Lee ◽  
Sang-Mo Koo ◽  
Jae-Geun Ha ◽  
...  
Keyword(s):  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Piezoelectric Materials ◽  
Lead Free ◽  
Electromechanical Coupling Coefficient ◽  
Substitution Effects ◽  
Sensors And Actuators ◽  
Device Applications ◽  
Piezoelectric Devices ◽  
Piezoelectric Charge

In this research, substitution effects of BiAlO3 with (Bi, Na)TiO3 piezoelectric ceramics was investigated for the sensors and actuators applications. (Bi,Na)TiO3 material has been employed for the piezoelectric devices applications because of their high piezoelectric charge constant, d33, of 88 pC/N, electromechanical coupling coefficient, kp, of 22% and inverse piezoelectric charge constant of 498 pm/V. As a piezoelectric material, (Bi, Na)TiO3 has perovskite structure with tetragonal basis. The improvement of piezoelectric and inverse piezoelectric properties is important for industrial device applications. Therefore, in this research, we have tried to increase functional and electrical properties of (Bi, Na)TiO3 piezoelectric materials by substituting BiAlO3 dopants. As a result, the piezoelectric constant was increased up to 140 pC/N, and the densification was increased up to 5.92 g/cm3 .

scholarly journals Progress in the Applications of Smart Piezoelectric Materials for Medical Devices

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2754
Author(s):  
Angelika Zaszczyńska ◽  
Arkadiusz Gradys ◽  
Paweł Sajkiewicz
Keyword(s):  
Medical Devices ◽  
Smart Materials ◽  
Piezoelectric Effect ◽  
Piezoelectric Materials ◽  
Mechanical Energy ◽  
Neural Tissue ◽  
Medical Industry ◽  
Neural Tissue Engineering ◽  
Sensors And Actuators ◽  
Energy Harvesting Devices

Smart piezoelectric materials are of great interest due to their unique properties. Piezoelectric materials can transform mechanical energy into electricity and vice versa. There are mono and polycrystals (piezoceramics), polymers, and composites in the group of piezoelectric materials. Recent years show progress in the applications of piezoelectric materials in biomedical devices due to their biocompatibility and biodegradability. Medical devices such as actuators and sensors, energy harvesting devices, and active scaffolds for neural tissue engineering are continually explored. Sensors and actuators from piezoelectric materials can convert flow rate, pressure, etc., to generate energy or consume it. This paper consists of using smart materials to design medical devices and provide a greater understanding of the piezoelectric effect in the medical industry presently. A greater understanding of piezoelectricity is necessary regarding the future development and industry challenges.

scholarly journals Enhanced Ferroelectric and Piezoelectric Properties of (1−x)PMN-xPT Ceramics Based on a Partial Oxalate Process

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2247 ◽  
Author(s):  
Jinhwan Kim ◽  
Sanghyun Yoon ◽  
Jae-Hoon Ji ◽  
Young-Ho Ko ◽  
Kyung-Ho Cho ◽  
...  
Keyword(s):  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Sintering Temperature ◽  
Piezoelectric Materials ◽  
Pyrochlore Phase ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Ferroelectric Ceramics ◽  
Calcination Process ◽  
Innovative Methods

The pyrochlore phase in ferroelectric and piezoelectric materials is the main obstacle device application due to its poor electrical properties. Especially, the pyrochlore phase is frequently observed in the perovskite-based metal-oxide materials including piezoelectric and ferroelectric ceramics, which are based on solid-state reaction methods for fabrication. To overcome these problems, advanced innovative methods such as partial oxalate process will be investigated. In this method, crystalized magnesium niobite (MN) and lead titanate (PT) powders will be coated with a certain amount of lead oxalate and, then, the calcination process can be carried out to form the PMN-PT without pyrochlore phase. In this study, (1−x)PMN-xPT ceramics near the morphotropic phase boundary (MPB), with compositions of x = 0.25–0.40, have been prepared employing the partial oxalate method at various temperatures. The crystalline, microstructure, and piezoelectric properties of (1−x)PMN-xPT ceramics depending on the sintering temperature were intensively investigated and discussed. By optimizing the sintering temperature and compositions from the PMN-PT ceramics, the maximum value of the piezoelectric charge coefficient (d33) of 665pC/N, planar electromechanical coupling factor (kp) of 77.8%, dielectric constant (εr) of 3230, and remanent polarization (Pr) of 31.67 μC/cm2 were obtained.

Piezoelectric properties of 0-3 ceramic/polar polymer composites

1992 ◽  
Vol 276 ◽  
Author(s):  
C. Dias ◽  
D. K. Das-Gupta
Keyword(s):  
Lead Titanate ◽  
Electromechanical Coupling ◽  
Piezoelectric Effect ◽  
Broad Band ◽  
Electromechanical Coupling Factor ◽  
Coupling Factor ◽  
Ferroelectric Ceramics ◽  
Ceramic Powders ◽  
Film Form ◽  
Polar Polymer

ABSTRACTFerroelectric ceramics such as PZT, while exhibiting strong piezoelectric effect, have the disadvantages of a high acoustic impedance, difficulty to miniaturize and not being suitable to broad band ultrasonic applications. Polar ferroelectric polymer such as PVDF and its copolymers which can be obtained in thin film form, have low mechanical Q and low acoustical impedance although their piezoelectric coefficients are significantly lower than those of the piezoelectric ceramics. Composites of piezoelectric ceramic powders, such as PZT and Calcium modified Lead Titanate (PT) in a matrix of P(VDF/TrFE) have been fabricated in our laboratory, in order to Investigate whether these materials could have the low acoustic, broad band properties of the polymers whilst retaining the high piezoelectric coefficients of the ceramics. In the present paper the results of a study of the electromechanical coupling factor (kt), the quality factor (Qm) as well as the gh and dh piezoelectric coefficients of these 0-3 composites poled both by corona and by the conventional method are given.

scholarly journals Vibration Analysis of Rotating Wind Turbine Blades Based on Piezoelectric Materials

2021 ◽  
Vol 26 (1) ◽  
pp. 49-55
Author(s):  
Ben Jing ◽  
Wang Hao
Keyword(s):  
Angular Velocity ◽  
Wind Turbine ◽  
Variable Coefficient ◽  
Piezoelectric Effect ◽  
Piezoelectric Materials ◽  
Mechanical Energy ◽  
Turbine Blades ◽  
Flexible Beam ◽  
Wind Turbine Blades ◽  
Sensors And Actuators

Piezoelectric materials have a piezoelectric effect that converts mechanical energy into electrical energy. In this paper, the blades of the rotating wind turbine are simplified as flexible beams fixed on the rotating wheels, and piezoelectric ceramics are added to the beams as sensors and actuators respectively to establish an analysis model of the vibration behavior of the piezoelectric sandwich rotating wind turbine blades. Based on Newton's second law, different accelerations are added to the rotating wheel to obtain the differential equation of a vibration variable coefficient. The fourth order Runge-Kutta method is used to solve variable coefficient differential equations. The hypothetical modal method is applied to solve the displacement of the free end of the flexible beam. A numerical simulation is also carried out to analyse the magnitude and change trend of the voltage output by adding piezoelectric materials at different angular velocities. The results show that the greater the rotational angular velocity, the greater the displacement of the free end of the flexible beam, and the greater the voltage due to the piezoelectric effect of the piezoelectric material. When the rotation angular velocity reaches a stable value, the displacement of the free end and the generated voltage will also reach a stable value.

Crack Surface Frictional Contact Modelling in Piezoelectric Materials

2018 ◽  
Vol 774 ◽  
pp. 607-612
Author(s):  
Luis Rodríguez-Tembleque ◽  
Felipe García-Sánchez ◽  
Andrés Sáez
Keyword(s):  
Shape Control ◽  
Electromechanical Coupling ◽  
Crack Surface ◽  
Piezoelectric Effect ◽  
Piezoelectric Materials ◽  
Laminated Composite ◽  
Operational Conditions ◽  
Contact Formulation ◽  
Influence Coefficients ◽  
Energy Harvesting Devices

Piezoelectric materials exhibit an electromechanical coupling which allows for their use assensors or energy harvesting devices (direct piezoelectric effect) or actuators and shape control de-vices (inverse piezoelectric effect). They are applied in many technological sectors of current interestsuch as the aerospace and automotive industries, and they are generally constructed in block form orin a thin laminated composite. The study of the integrity of such materials in their various forms andsmall sizes is still a challenge nowadays. To gain a better understanding of these systems, this workpresents a crack surface contact formulation which makes it possible to study the integrity of theseadvanced materials under more realistic crack surface multifield operational conditions. The formu-lation uses the BEM for computing the elastic influence coefficients and contact operators over theaugmented Lagrangian to enforce contact constraints on the crack surface, in the presence of electricfields. The capabilities of this methodology are illustrated solving a benchmark problem.

scholarly journals Piezoelectric Energy Harvesting Solutions: A Review

Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3512 ◽  
Author(s):  
Corina Covaci ◽  
Aurel Gontean
Keyword(s):  
Energy Harvesting ◽  
Piezoelectric Effect ◽  
Piezoelectric Transducers ◽  
Piezoelectric Energy Harvesting ◽  
Piezoelectric Energy ◽  
Direct Piezoelectric Effect ◽  
Harvesting Technique ◽  
Different Shapes ◽  
Piezoelectric Devices ◽  
Review Current

The goal of this paper is to review current methods of energy harvesting, while focusing on piezoelectric energy harvesting. The piezoelectric energy harvesting technique is based on the materials’ property of generating an electric field when a mechanical force is applied. This phenomenon is known as the direct piezoelectric effect. Piezoelectric transducers can be of different shapes and materials, making them suitable for a multitude of applications. To optimize the use of piezoelectric devices in applications, a model is needed to observe the behavior in the time and frequency domain. In addition to different aspects of piezoelectric modeling, this paper also presents several circuits used to maximize the energy harvested.

scholarly journals Stress-driven two-phase integral elasticity for Timoshenko curved beams

2021 ◽  
pp. 239779142199051
Author(s):  
Marzia S Vaccaro ◽  
Francesco P Pinnola ◽  
Francesco Marotti de Sciarra ◽  
Marko Canadija ◽  
Raffaele Barretta
Keyword(s):  
Solution Procedure ◽  
Small Scale ◽  
Curved Beams ◽  
Sensors And Actuators ◽  
Two Phase ◽  
Design And Optimization ◽  
Local Responses ◽  
Size Dependent ◽  
Classical Boundary ◽  
Phase Integral

In this research, the size-dependent static behaviour of elastic curved stubby beams is investigated by Timoshenko kinematics. Stress-driven two-phase integral elasticity is adopted to model size effects which soften or stiffen classical local responses. The corresponding governing equations of nonlocal elasticity are established and discussed, non-classical boundary conditions are detected and an effective coordinate-free solution procedure is proposed. The presented mixture approach is elucidated by solving simple curved small-scale beams of current interest in Nanotechnology. The contributed results could be useful for design and optimization of modern sensors and actuators.

Longitudinal piezoelectric effect and hydrostatic response in novel laminar composites based on ferroelectric ceramics

2019 ◽  
Vol 45 (17) ◽  
pp. 22241-22248 ◽  
Author(s):  
A.A. Nesterov ◽  
V.Yu. Topolov ◽  
M.I. Tolstunov ◽  
A.N. Isaeva
Keyword(s):  
Piezoelectric Effect ◽  
Ferroelectric Ceramics ◽  
Laminar Composites
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