Generalized homogenization model of piezoelectric materials for ultrasonic transducer applications

2021 ◽  
pp. 002199832110588
Author(s):  
Fidéle Léopold Hanse Wampo ◽  
Richard Ntenga ◽  
Joseph Yves Effa ◽  
Yuri Lapusta ◽  
Guy Edgar Ntamack ◽  
...  
Keyword(s):  
Coupling Coefficient ◽  
Volume Fraction ◽  
Piezoelectric Materials ◽  
Ultrasonic Transducer ◽  
Trade Off ◽  
Analytical Results ◽  
Homogenization Model ◽  
A Performance

Although piezocomposite (PC) materials have increasingly attracted researchers, there is still a need to properly and easily derive their properties. We develop a generalized homogenization model (GHM) that accounts for Smith and Cha approaches to evaluate the equivalent characteristics of piezocomposites. This method could be applied to all connectivities patterns, but restricted herein to 2-2 and 1-3 piezocomposites for comparison with Smith (1-3) and Cha (2-2) analytical results. In the proposed GHM is a parameter θ, is changed for various connectivities. The 1-3 and 2-2 PZT-7A/Araldite D (PCs) data are used and equivalent characteristics of these Pcs are determined as function of volume fraction of PZT-7A piezoelectric. Results show that the electromechanical coefficients are well fitted by Voigt and Reuss models. Results obtained for some parameters show that the proposed GHM is consistent with the analytical existing models used for the 1-3 and 2-2 connectivities and is in line with measured values from Chan and Unsworth (1989). Based on the GHM 2-2 configuration results of piezocomposite materials, the electroacoustic responses of transducers having some of these properties are simulated using the KLM model. A performance trade-off was chosen, resulting in an improved thickness coupling coefficient and a lowered acoustical impedance, and a similar approach as that on a pure PZT-7A.

On a performance-robustness trade-off intrinsic to the natural anti-windup problem

Automatica ◽  
2006 ◽  
Vol 42 (11) ◽  
pp. 1849-1861 ◽  
Author(s):  
Sergio Galeani ◽  
Andrew R. Teel
Keyword(s):  
Trade Off ◽  
Performance Robustness ◽  
A Performance

scholarly journals FEM Analysis of Various Multilayer Structures for CMOS Compatible Wearable Acousto-Optic Devices

Sensors ◽  
2021 ◽  
Vol 21 (23) ◽  
pp. 7863
Author(s):  
Mehwish Hanif ◽  
Varun Jeoti ◽  
Mohamad Radzi Ahmad ◽  
Muhammad Zubair Aslam ◽  
Saima Qureshi ◽  
...  
Keyword(s):  
Coupling Coefficient ◽  
Figure Of Merit ◽  
Electromechanical Coupling ◽  
Piezoelectric Materials ◽  
Fem Analysis ◽  
Film Structure ◽  
Multilayer Structures ◽  
Electromechanical Coupling Coefficient ◽  
Materials Used ◽  
The Individual

Lately, wearable applications featuring photonic on-chip sensors are on the rise. Among many ways of controlling and/or modulating, the acousto-optic technique is seen to be a popular technique. This paper undertakes the study of different multilayer structures that can be fabricated for realizing an acousto-optic device, the objective being to obtain a high acousto-optic figure of merit (AOFM). By varying the thicknesses of the layers of these materials, several properties are discussed. The study shows that the multilayer thin film structure-based devices can give a high value of electromechanical coupling coefficient (k2) and a high AOFM as compared to the bulk piezoelectric/optical materials. The study is conducted to find the optimal normalised thickness of the multilayer structures with a material possessing the best optical and piezoelectric properties for fabricating acousto-optic devices. Based on simulations and studies of SAW propagation characteristics such as the electromechanical coupling coefficient (k2) and phase velocity (v), the acousto-optic figure of merit is calculated. The maximum value of the acousto-optic figure of merit achieved is higher than the AOFM of all the individual materials used in these layer structures. The suggested SAW device has potential application in wearable and small footprint acousto-optic devices and gives better results than those made with bulk piezoelectric materials.

Piezoelectric Properties of PZT-5 Fiber/Epoxy Resin 1-3 Composites

2011 ◽  
Vol 239-242 ◽  
pp. 486-489
Author(s):  
Ling Fang Xu ◽  
Wen Chen ◽  
Jing Zhou ◽  
Chang Ping Yang
Keyword(s):  
Epoxy Resin ◽  
Coupling Coefficient ◽  
Piezoelectric Properties ◽  
Volume Fraction ◽  
Mechanical Quality Factor ◽  
Casting Method ◽  
Anisotropic Property ◽  
Niobium Doped ◽  
Mechanical Quality ◽  
Method Effects

Niobium doped Pb(Zr,Ti)O3fiber/epoxy resin 1-3 composites with different ceramic volume fraction of 10-85% were fabricated by filling-casting method. Effects of ceramic volume fraction on electric properties were investigated. For a typical 30% ceramic content composite, the thickness coupling coefficientkt, mechanical quality factorQm, acoustic impedanceZmand anisotropic propertykt/kpwere 0.67, 0.55, 11.03 MRayl and 2.23, respectively.

scholarly journals Biodegradable nanofiber-based piezoelectric transducer

2019 ◽  
Vol 117 (1) ◽  
pp. 214-220 ◽  
Author(s):  
Eli J. Curry ◽  
Thinh T. Le ◽  
Ritopa Das ◽  
Kai Ke ◽  
Elise M. Santorella ◽  
...  
Keyword(s):  
Medical Devices ◽  
Piezoelectric Materials ◽  
Ultrasonic Transducer ◽  
Implantable Medical Devices ◽  
Safety Issues ◽  
Highly Sensitive ◽  
Implanted Medical Devices ◽  
Device Applications ◽  
Processing Device ◽  
Implanted Devices

Piezoelectric materials, a type of “smart” material that generates electricity while deforming and vice versa, have been used extensively for many important implantable medical devices such as sensors, transducers, and actuators. However, commonly utilized piezoelectric materials are either toxic or nondegradable. Thus, implanted devices employing these materials raise a significant concern in terms of safety issues and often require an invasive removal surgery, which can damage directly interfaced tissues/organs. Here, we present a strategy for materials processing, device assembly, and electronic integration to 1) create biodegradable and biocompatible piezoelectric PLLA [poly(l-lactic acid)] nanofibers with a highly controllable, efficient, and stable piezoelectric performance, and 2) demonstrate device applications of this nanomaterial, including a highly sensitive biodegradable pressure sensor for monitoring vital physiological pressures and a biodegradable ultrasonic transducer for blood–brain barrier opening that can be used to facilitate the delivery of drugs into the brain. These significant applications, which have not been achieved so far by conventional piezoelectric materials and bulk piezoelectric PLLA, demonstrate the PLLA nanofibers as a powerful material platform that offers a profound impact on various medical fields including drug delivery, tissue engineering, and implanted medical devices.

scholarly journals An MHD Fluid Flow over a Porous Stretching/Shrinking Sheet with Slips and Mass Transpiration

Micromachines ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 116
Author(s):  
A. B. Vishalakshi ◽  
U. S. Mahabaleshwar ◽  
Ioannis E. Sarris
Keyword(s):  
Fluid Flow ◽  
Prandtl Number ◽  
Thermal Radiation ◽  
Biot Number ◽  
Volume Fraction ◽  
Heat Transfer Analysis ◽  
Shrinking Sheet ◽  
Physical Parameters ◽  
Graphical Representations ◽  
Analytical Results

In the present paper, an MHD three-dimensional non-Newtonian fluid flow over a porous stretching/shrinking sheet in the presence of mass transpiration and thermal radiation is examined. This problem mainly focusses on an analytical solution; graphene water is immersed in the flow of a fluid to enhance the thermal efficiency. The given non-linear PDEs are mapped into ODEs via suitable transformations, then the solution is obtained in terms of incomplete gamma function. The momentum equation is analyzed, and to derive the mass transpiration analytically, this mass transpiration is used in the heat transfer analysis and to find the analytical results with a Biot number. Physical significance parameters, including volume fraction, skin friction, mass transpiration, and thermal radiation, can be analyzed with the help of graphical representations. We indicate the unique solution at stretching sheet and multiple solution at shrinking sheet. The physical scenario can be understood with the help of different physical parameters, namely a Biot number, magnetic parameter, inverse Darcy number, Prandtl number, and thermal radiation; these physical parameters control the analytical results. Graphene nanoparticles are used to analyze the present study, and the value of the Prandtl number is fixed to 6.2. The graphical representations help to discuss the results of the present work. This problem is used in many industrial applications such as Polymer extrusion, paper production, metal cooling, glass blowing, etc. At the end of this work, we found that the velocity and temperature profile increases with the increasing values of the viscoelastic parameter and solid volume fraction; additionally, efficiency is increased for higher values of thermal radiation.

scholarly journals Design and analysis of energy harvester using MEMS based Cantilever with variable perforations

2017 ◽  
Vol 7 (1.5) ◽  
pp. 141
Author(s):  
G.R.K Prasad ◽  
N. Siddaiah ◽  
P. Sanjeev ◽  
A. Raviteja ◽  
P. Karunya ◽  
...  
Keyword(s):  
Coupling Coefficient ◽  
Output Voltage ◽  
Energy Harvester ◽  
Piezoelectric Properties ◽  
Piezoelectric Materials ◽  
Crystal Properties ◽  
Displacement Sensitivity ◽  
Eigen Frequencies ◽  
Output Capacitance ◽  
Pzt Thick Film

This paper represents the design and analysis of energy harvester using MEMS based cantilever with PMN-PT single crystal properties which has excellent piezoelectric properties while compared to other piezoelectric materials like PZT thick film. The design is analysed using COMSOL multi physics which is used for many MEMS operations and also problems related to physics with many mathematical calculations with better efficiency and ease to design. We designed a cantilever with PMN-PT properties which has good coupling coefficient and increased perforations in number in form of square and circular. We tested the displacement sensitivity i.e., the variation of displacement at different eigen frequencies with increase in number of perforations. We observe output voltage by designing electromechanical analysis and variation in output capacitance of  2 .41 x 10-22 Farads is observed.

Dynamic Magnetomechanical Properties of Terfenol-D/Epoxy 1-3 Particulate Composites

2002 ◽  
Author(s):  
Siu Wing Or ◽  
Geoffrey P. McKnight ◽  
Nersesse Nersessian ◽  
Gregory P. Carman
Keyword(s):  
Coupling Coefficient ◽  
Elastic Moduli ◽  
Volume Fraction ◽  
Bias Field ◽  
Particulate Composites ◽  
Dynamic Strain ◽  
Monolithic Material ◽  
Different Types ◽  
Strain Coefficient ◽  
Magnetomechanical Coupling

This paper describes the effect of particulate crystallographic orientation on the dynamic magnetomechanical properties of Terfenol-D/epoxy 1–3 magnetostrictive particulate composites. Two different types of composites with approximately 50% Terfenol-D volume fraction were fabricated for comparison with [112]-textured monolithic Terfenol-D. In the first type, needle-shaped, [112]-oriented particles cut from the monolithic Terfenol-D were used and in the second type, irregular-shaped, randomly oriented particles ball-milled from the monolithic material were employed. Elastic moduli (E33H and E33B), dynamic strain coefficient (d33), and magnetomechanical coupling coefficient (k33) were investigated as a function of bias field. Both composites demonstrate similar property trends with the negative-ΔE, d33, and k33 values maximizing near 30 kA/m. The maximum values achieved in the oriented type are up to 67% larger than the non-oriented type and approaches 65% of the monolithic Terfenol-D. The property improvement in the oriented type is shown to be attributed to [112] preferential particulate orientation.

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