scholarly journals Static Electromechanical Characteristic of a Three-Layer Circular Piezoelectric Transducer

Sensors ◽  
2019 ◽  
Vol 20 (1) ◽  
pp. 222 ◽  
Author(s):  
Grzegorz Mieczkowski ◽  
Andrzej Borawski ◽  
Dariusz Szpica

The paper presents research related to the functional features of a novel three-layer circular piezoelectric actuator/sensor. The outer layers of the transducer are made of non-piezoelectric material. The middle layer comprises two elements—a piezoelectric disk, and a ring made of non-piezoelectric material. The additional external passive layer has a very important function; it protects the transducer’s electrical components against damage caused by external factors. Also, if sparking on the transducer wires or electrodes occurs, this layer prevents fire. So far, there is no analytical model for such a transducer. Closed-form analytical equations are important tools for predicting and optimizing the operation of devices. Thus, using both the Plate Theory and constitutive equations of piezoelectric materials, an analytical formula describing transducer deflection as a function of electrical loads has been found (electromechanical characteristic of the transducer). In addition, it is worth noting that under certain assumptions, the developed analytical model can also be used for two-layer transducers. The tests carried out show satisfactory compliance of the results obtained through the developed solution with both literature data and numerical data. Moreover, based on the obtained analytical model, the effect of selected non-dimensional variables on the actuator performance has been examined. These parameters include dimensions and mechanical properties of both piezoelectric disk and passive plates and strongly influence the behavior of the transducer.

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1436
Author(s):  
Arian Nowbahari ◽  
Avisek Roy ◽  
Muhammad Nadeem Akram ◽  
Luca Marchetti

In this paper, we investigate the accuracy of the approximated analytical model currently utilized, by many researchers, to describe the depletion region width in planar junctionless transistors (PJLT). The proposed analysis was supported by numerical simulations performed in COMSOL Multiphysics software. By comparing the numerical results and the approximated analytical model of the depletion region width, we calculated that the model introduces a maximum RMS error equal to 90 % of the donor concentration in the substrate. The maximum error is achieved when the gate voltage approaches the threshold voltage ( V t h ) or when it approaches the flat band voltage ( V F B ) of the transistor. From these results, we concluded that this model cannot be used to determine accurately the flat-band and the threshold voltage of the transistor, although it represents a straightforward method to estimate the depletion region width in PJLT. By using the approximated analytical model, we extracted an analytical formula, which describes the electron concentration at the ideal boundary of the depletion region. This formula approximates the numerical data extracted from COMSOL with a relative error lower than 1 % . The proposed formula is in our opinion, as useful as the formula of the approximated analytical model because it allows for estimating the position of the depletion region also when the drain and source terminals are not grounded. We concluded that the analytical formula proposed at the end of this work could be useful to determine the position of the depletion region boundary in numerical simulations and in graphical representations provided by COMSOL Multiphysics software.


2008 ◽  
Vol 1075 ◽  
Author(s):  
Mahmoud Al Ahmad ◽  
Fabio Coccetti ◽  
Robert Plana

AbstractThis paper will first address the piezoelectric material characterization using a capacitance measurement technique. An original simple and efficient technique for the determination of the d33 piezoelectric coefficient of lead zirconate titanate thin films is described. Classical capacitor plate theory and piezoelectric material analysis are used to calculate the capacitance variation in lead zirconate titanate film, enabling piezo-electric coefficient to be determined. The technique outlined here avoids the use of mechanical/optical apparatus that may require heavy preparation of sample substrate geometry. Then, this work also treats design and fabrication issues associated with innovative tunable front-end components which combine two different ceramic technologies, namely multilayer ceramic circuit boards (low temperature cofired ceramics or LTCC) and piezoelectric actuator technology within a single device.


2000 ◽  
Author(s):  
Jeffrey S. N. Paine ◽  
David S. Bennett ◽  
Carlos E. Cuadros

Abstract As piezoelectric actuators are developed for high strokes and/or high force applications, the amount of piezoelectric material used in the actuator must also increase. Reducing the size of drive electronics becomes difficult using traditional linear power electronics packages when applications require as much as 40 μF of piezoelectric load. In order to efficiently drive piezoelectric actuator systems, bi-directional systems (drivers that recover the energy put into the piezoelectric capacitor) must be used. Since less than 10% of the power going into the piezoelectric actuator is real versus the large reactive load used to power the piezoelectric materials, bidirectional systems have a much higher efficiency. A comparison is made between traditional linear and PWM amplifier systems and tailored piezoelectric bi-directional driver systems. Bi-directional systems have power dissipation levels up to 1/8th those of traditional linear amplifier systems. In the course of the research both linear and PWM concepts were investigated. A rationale for comparing the overall efficiency of drive electronics systems is presented. Some innovative efficient concepts for piezoelectric system drivers are presented and discussed.


2002 ◽  
Vol 40 (6) ◽  
pp. 487-501
Author(s):  
M. Mofid ◽  
S. Azizpour ◽  
S.L. McCabe

2018 ◽  
Vol 29 (9) ◽  
pp. 2008-2026 ◽  
Author(s):  
Andres E Rivero ◽  
Paul M Weaver ◽  
Jonathan E Cooper ◽  
Benjamin KS Woods

Camber morphing aerofoils have the potential to significantly improve the efficiency of fixed and rotary wing aircraft by providing significant lift control authority to a wing, at a lower drag penalty than traditional plain flaps. A rapid, mesh-independent and two-dimensional analytical model of the fish bone active camber concept is presented. Existing structural models of this concept are one-dimensional and isotropic and therefore unable to capture either material anisotropy or spanwise variations in loading/deformation. The proposed model addresses these shortcomings by being able to analyse composite laminates and solve for static two-dimensional displacement fields. Kirchhoff–Love plate theory, along with the Rayleigh–Ritz method, are used to capture the complex and variable stiffness nature of the fish bone active camber concept in a single system of linear equations. Results show errors between 0.5% and 8% for static deflections under representative uniform pressure loadings and applied actuation moments (except when transverse shear exists), compared to finite element method. The robustness, mesh-independence and analytical nature of this model, combined with a modular, parameter-driven geometry definition, facilitate a fast and automated analysis of a wide range of fish bone active camber concept configurations. This analytical model is therefore a powerful tool for use in trade studies, fluid–structure interaction and design optimisation.


Author(s):  
Bo Lin ◽  
Molong Duan ◽  
Chinedum E. Okwudire ◽  
Jason S. Wou

The friction behavior of rolling ball machine components like linear ball bearings is very important to their functionality. For instance, differences in linear velocity of balls induces ball-to-ball contact in certain circumstances, resulting in significant increases and variations in friction. In this paper, an improved analytical formula for determining the linear velocity of balls in four-point-contact linear ball bearings is derived as a function of contact angle deviations and contact forces. The analytical formula is validated against a comprehensive friction model in the literature and shown to be in good agreement, while an oversimplified analytical model proposed by the authors in prior work is shown to be inaccurate. A case study is presented where insights gained from the derived analytical formula are used to mitigate velocity difference of balls in a linear ball bearing which otherwise would experience ball-to-ball contact.


Author(s):  
Muturi G. Muriuki ◽  
William W. Clark

This paper presents the design and analysis of a cantilever beam resonator that is driven by a piezoelectric material. The beam is a bimorph structure with Lead Zirconate Titanate (PZT) and stainless steel or aluminum layers. The PZT layer is electroded in segments to form a sensor and actuator pair for feedback to drive the resonator. An additional PZT segment is used, in conjunction with a capacitive shunt circuit, to change the vibration frequency of the resonator. The study is based on an analytical model of the beam and experimental testing.


Author(s):  
Y. H. Park ◽  
I. Hijazi

Abstract Damage monitoring in pipes and pressure vessels are important to ensure safety and reliability of these structures. Structural damage monitoring based on an actuator-sensor system is a promising technology to obtain real-time information for structural condition. Since piezoelectric materials in electromechanical systems can detect mechanical responses such stress and deformation as a sensor or perform a defined work as an actuator, piezoelectric actuators/sensors are extensively used in damage detection. In the design of piezoelectric actuators and sensors, it is important to know the properties of the piezoelectric material, in particular, piezoelectric constants to predict its actuation/sensing performance. In this study we determine a piezoelectric constant of ZnO using molecular dynamics simulations. We introduced a shell degree of freedom to the core-only atomic potential to enable polarization of the ion caused by an electric field. This modeling technique allowed for accurate piezoelectric response of the molecular structure.


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