Effects of finite dimension on the electro-elastic responses of an interface electrode in a piezoelectric actuator

Li, Y.-D.,Lee, K.Y. WILEY-VCH Verlag 2010 Zeitschrift für angewandte mathematik und mec Vol.90 No.1

<P>All piezoelectric actuators are of finite dimension. The effect of finite geometry on the electro-elastic responses is of significance to the design of practical actuators. Electromechanical model is established for an interface electrode in a piezoelectric actuator with finite dimension. The methods of infinite series and Cauchy singular integral equation are employed to perform the electro-elastic analysis. The accuracy of numerical calculation is analyzed and the suitability of the present methods is discussed. Parametric studies on the electro-elastic intensity factors yield three conclusions. (a) A central electrode rather than an off-center one can help to enhance the structural reliability. (b) For an actuator with central electrode, it is better to make the interface twice as long as the electrode. For an actuator with periodical interface electrodes, the optimal allocation of electrodes is to make the space identical to the electrode length. (c) The thickness of the piezoelectric layer should be at least a quarter of the electrode length.</P> <B>Graphic Abstract</B> <P>All piezoelectric actuators are of finite dimension. The effect of finite geometry on the electro-elastic responses is of significance to the design of practical actuators. Electromechanical model is established for an interface electrode in a piezoelectric actuator with finite dimension. The methods of infinite series and Cauchy singular integral equation are employed to perform the electro-elastic analysis. The accuracy of numerical calculation is analyzed and the suitability of the present methods is discussed. Parametric studies on the electro-elastic intensity factors yield three conclusions. (a) A central electrode rather than an off-center one can help to enhance the structural reliability. (b) For an actuator with central electrode, it is better to make the interface twice as long as the electrode. For an actuator with periodical interface electrodes, the optimal allocation of electrodes is to make the space identical to the electrode length. (c) The thickness of the piezoelectric layer should be at least a quarter of the electrode length.</P> <img src='wiley_img/00442267-2010-90-1-ZAMM200900328-content328.gif' alt='wiley_img/00442267-2010-90-1-ZAMM200900328-content328'>

적층 압전 액추에이터의 전기-기계적 특성 분석

하기홍(Gi Hong Ha),이수일(Soo Il Lee) 한국소음진동공학회 2014 한국소음진동공학회 학술대회논문집 Vol.2014 No.4

The piezoelectric materials convert from mechanical energy to electrical energy. The piezoelectric materials are used in various engineering applications such as piezoelectric ultrasonic actuators. Since the piezoelectric coupling characteristics of the actuator systems should be considered at the initial design stage, it is essential to analyze the piezoelectric coupling characteristics of the ultrasonic actuators. In this study, we analyzed the electromechanical characteristics of piezoelectric stacked actuator using the equivalent circuit model with modal mass stiffness parameters. It was compared the admittance of piezoelectric stack actuators with the analytical circuit model and the finite element model. Also, the coupling coefficient of piezoelectric stack actuator was discussed according to the number of stacks of actuators.

Study of damping in 5kWh superconductor flywheel energy storage system using a piezoelectric actuator

Jang, H.K.,Song, D.,Kim, S.B.,Han, S.C.,Sung, T.H. North-Holland 2012 Physica. C, Superconductivity Vol.475 No.-

A 5kWh superconductor flywheel energy storage system (SFES) has advantages in terms of high electrical energy density, environmental affinity and long life. However, the SFES has disadvantage that electromagnetic damper is needed because superconducting bearings do not have enough damping coefficient. The purpose of this experiment is to develop a method of damping the vibration of the SFES. A piezoelectric actuator was attached to a superconducting bearing system for feasibility test in order to make it as a damper of the SFES. For this experiment, a cylindrical permanent magnet (PM) 40mm in diameter and 10mm height was used as a rotor, a high-temperature superconductor bulk (HTS bulk) with dimensions 40mmx40mmx15mm was used as a stator, and two vibration exciters (an upper and a lower vibration exciter) and a piezoelectric actuator were used. The PM was fixed on the upper vibration exciter. The HTS bulk was fixed on either the lower vibration exciter to test for damping in the feasibility test, or on the piezoelectric actuator for the actual SFES. The conditions of this experiment included various voltage outputs of a power amplifier to the lower vibration exciter, moving distances of the piezoelectric actuator which are displacements of the HTS bulk, and phase differences between the upper and lower vibration exciter or the piezoelectric actuator. The damping feasibility test was conducted with a 300μm gap between the PM and HTS bulk with a PM vibration of 30μm. For the actual SFES test, the gap between the PM and HTS bulk was 1.6mm and the PM vibration was 25μm. The following conditions were conducted to optimize: an appropriate voltage input to the lower vibration exciter or a displacement of piezoelectric actuator and an appropriate phase difference. When the piezoelectric actuator was used, the damping effect was greatly improved up to 92.32% which a displacement of damped PM was 1.92μm.

Control of free vibration with piezoelectric materials: Finite element modeling based on Timoshenko beam theory

Song, Myung-Kwan,Noh, Hyuk-Chun,Kim, Sun-Hoon,Han, In-Seon Techno-Press 2005 Structural Engineering and Mechanics, An Int'l Jou Vol.19 No.5

In this study, a new smart beam finite element is proposed for the finite element modeling of beam-type smart structures that are equipped with bonded plate-type piezoelectric sensors and actuators. Constitutive equations for the direct piezoelectric effect and converse piezoelectric effect of piezoelectric materials are considered in the formulation. By using a variational principle, the equations of motion for the smart beam finite element are derived. The proposed 2-node beam finite element is an isoparametric element based on Timoshenko beam theory. The proposed smart beam finite element is applied to the free vibration control adopting a constant gain feedback scheme. The electrical force vector, which is obtained in deriving an equation of motion, is the control force equivalent to that in existing literature. Validity of the proposed element is shown through comparing the analytical results of the verification examples with those of other previous researchers. With the use of smart beam finite elements, simulation of free vibration control is demonstrated by sensing the voltage of the piezoelectric sensors and by applying the voltages to the piezoelectric actuators.

Simulation and Design of a Multilayer Piezoelectric Actuator

Lee, Kabsoo,Yoo, Juhyun,Lee, Sangho,Hong, Jaeil The Korean Institute of Electrical and Electronic 2017 Transactions on Electrical and Electronic Material Vol.18 No.3

In this study, two- and three-layer ceramic piezoelectric actuators were designed and simulated according to SUS316 thickness, actuator width, and mass using ATILA software in order to develop a piezoelectric actuator for haptic application. Numerical modelling based on the finite element method was performed to find the resonance frequencies and modal shapes of the actuator. The resonance frequency was affected by the thickness of the SUS316 plate and mass. On the other hand, the width of the actuator did not have a significant impact. Maximum displacements were generated at the center of a haptic three-layer ceramic piezoelectric actuator. The two-layer ceramic piezoelectric actuator with a mass of 2.6 g was suitable as $16.28{\mu}m$ at 265 Hz for haptic sensation application.

Simulation and Design of a Multilayer Piezoelectric Actuator

이갑수,류주현,이상호,홍재일 한국전기전자재료학회 2017 Transactions on Electrical and Electronic Material Vol.18 No.3

In this study, two- and three-layer ceramic piezoelectric actuators were designed and simulated according toSUS316 thickness, actuator width, and mass using ATILA software in order to develop a piezoelectric actuator forhaptic application. Numerical modelling based on the finite element method was performed to find the resonancefrequencies and modal shapes of the actuator. The resonance frequency was affected by the thickness of theSUS316 plate and mass. On the other hand, the width of the actuator did not have a significant impact. Maximumdisplacements were generated at the center of a haptic three-layer ceramic piezoelectric actuator. The two-layerceramic piezoelectric actuator with a mass of 2.6 g was suitable as 16.28 μm㎛ at 265 Hz for haptic sensation application.

스피커 응용을 위한 적층형 압전 세라믹 액츄에이터 제조 및 특성

이민선,윤지선,박운익,홍연우,백종후,조정호,박용호,정영훈,Lee, Min-seon,Yun, Ji-sun,Park, Woon Ik,Hong, Youn-Woo,Paik, Jong Hoo,Cho, Jeong Ho,Park, Yong-Ho,Jeong, Young-Hun 한국전기전자재료학회 2016 전기전자재료학회논문지 Vol.29 No.10

Piezoelectric thick films of soft $Pb(Zr,Ti)O_3$ (PZT) based commercial material (S55) were fabricated using a conventional tape casting method. Ag-Pd electrodes were printed on the piezoelectric film at room temperature and all 5 layered films with a dimension of $12mm{\times}16mm$ were successfully laminated for a multi-layered piezoelectric ceramic actuator. The laminated specimens were co-fired at $1,100^{\circ}C$ for 1 h. A flat layered and dense microstructure was obtained for the $112{\mu}m$ thick piezoelectric actuator after sintering process. Thereafter, a prototype piezoelectric speaker was fabricated using the multi-layered piezoelectric ceramic actuator which can operate as a bimorph. Its SPL (sound pressure level) characteristic was also evaluated for speaker application. Frequency response revealed that the output SPL with a root mean square voltage of 10 V increased gradually to the highest peak of 87.5 dB for 1.5 kHz and exhibited a relatively stable behavior over the measured frequency range (${\leq}20kHz$) at a distance of 10 cm, implying that the fabricated piezoelectric speaker is potential for speaker applications.

Long Range and High Axial Load Capacity Nanopositioner Using Single Piezoelectric Actuator and Translating Supports

Juluri, Bala Krishna,Lin, Wu,Lim, Lennie E N Korean Society for Precision Engineering 2007 International Journal of Precision Engineering and Vol.8 No.4

Existing long range piezoelectric motors with friction based transmission mechanisms are limited by the axial load capacity. To overcome this problem, a new linear piezoelectric motor using one piezoelectric actuator combined with a novel stepping mechanism is reported in this paper. To obtain both long range and fine accuracy, dual positioning control strategy consisting of coarse positioning and fine positioning is used. Coarse positioning is used for long travel range by accumulating motion steps obtained by piezoelectric actuator. This is followed by fine positioning where required accuracy is obtained by fine motion displacement of piezoelectric actuator. This prototype is able to provide resolution of 20 nanometers and withstand a maximum axial load of 300N. At maximum load condition, the positioner can move forward to a travel distance of 5mm at a maximum speed of 0.4 mm/sec. This design of nanopositioner can be used in applications for ultra precision positioning and grinding operations where high axial force capacity is required.

Development of a Piezoelectric Pump for a Highly-precise Constant Flow Rate

함영복,서우석,오성진,박중호,윤소남,안국영 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.41

Recently, piezoelectric-driven small and micro-sized pumps have been developed for applications in microfluidics, bio-chemistry diagnostics, fuel cell systems, drug delivery, and high-power electronics cooling, etc. This paper describes a piezoelectric pump using a multilayered piezoelectric actuator for highly-precise constant flow rate. The design, fabrication, and basic characteristics of the developed piezoelectric pump are summarized. The proposed pump consists of a pump housing, a multilayered piezoelectric actuator, a valve sheet and a single check valve for an inlet port. The overall dimensions of the fabricated piezoelectric pump are 25 mm × 25 mm × 53 mm. Pumping characteristics were experimentally investigated. The fabricated pump achieved a no-load flow rate of 110 ml/min and a maximum output power of 130 mW at an applied voltage of 150 Vpp and a driving frequency of 700 Hz.

고상 단결정 성장법을 이용한 제 3 세대 압전 단결정의 개발 및 응용

이호용(Ho-Yong LEE) 한국세라믹학회 2021 세라미스트 Vol.24 No.3

Crystallographically engineered Relaxor-PT single crystals, specifically PMN-PT (Generation I) and PIN-PMN-PT/PMN-PZT (Generation II), offer much higher piezoelectric and electromechanical coupling coefficients (d33>1,500 pC/N, k33>0.9), when compared to polycrystalline PZT-5H ceramics (d33>600 pC/N, k33>0.75). Recently Ceracomp Co., Ltd. (www.ceracomp.com) has developed the solid-state single crystal growth (SSCG) technique and successfully fabricated Gen III PMN-PZT single crystals modified with acceptors or donors. The piezoelectric constants (d33) of (001) Gen III PMN-PZT single crystals were measured to be higher than 4,000 pC/N and thus about two times higher than those of PMN-PT/PZN-PT (Gen I) and PINPMN- PT/PMN-PZT (Gen II) single crystals. The Gen III PMN-PZT single crystals have been firstly applied to single crystal-epoxy composites, ultrasonic transducers, piezoelectric sensors, and piezoelectric actuators. In this paper we introduce the development of Gen III PMN-PZT single crystals, piezoelectric composites and multilayer single crystal actuators.