• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.4
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• pp.360-365
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• 2009

On this paper, piezoelectric generators using piezoelectric ceramics were designed and fabricated. Generators were made by attaching cymbal type metal plates on upper and bottom sides of a disc type piezoelectric ceramic. Generator converts wasting mechanical energy to electrical energy. Output voltage was increased when thickness of ceramic and displacement of vibration were increased. Temperature of the ceramic was increased when it generates, but the temperature rising was saturated at certain temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.169-170
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• 2008

On this paper, piezoelectric generators using piezoelectric ceramics were designed and fabricated. Generators were made by attaching cymbal type metal plates on upper and bottom sides of a disc type piezoelectric ceramic. Generator converts wasting mechanical energy to electrical energy. Output voltage was increased when thickness of ceramic and displacement of vibration were increased. Temperature of the ceramic was increased when it generates, but the temperature rising was saturated at certain temperature.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.270-273
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• 1996

This paper describes a type of piezoelectric transformer with improved design principles. It consists of a thin rectangular piezoelectric ceramic plate having two input electrodes and one output electrode. The length of each input and output electrode is nearly one third of that of piezoelectric transformer itself. In the driving section, the ceramic plate is poled in the thickness direction reversely with each other, and has electrodes on both main faces. The electric input near its fundamental resonance frequency is applied to the driving section in parallel and the output voltage from the generating section is connected to the resistor load. Its equivalent circuit is derived from the Mason\`s model. The frequency characteristics near the resonance frequency under no load have been investigated. Moreover, using this piezoelectric transformer we measured the LCD backlight characteristics.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.8
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• pp.501-507
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• 2017

A unimorph piezoelectric cantilever generator with an interdigitated electrode (IDE) was developed for vibration energy harvester applications driven in the longitudinal mode. Hard lead zirconate titanate (PZT) ceramic with a high $Q_m$ of 1,280 was used as the piezoelectric active material. Ten PZT sheets produced by tape casting were laminated and co-fired with an Ag/Pd IDE at $1,050^{\circ}C$ for 2 h. The approximately $280{\mu}m$-thick co-fired PZT laminate with the IDE was attached to a stainless steel substrate with an adhesive epoxy for the fabrication of an IDE unimorph cantilever. Its energy harvesting characteristics were evaluated: an output power of $1.1{\mu}W$ at 120 Hz across the resistive load of $700k{\Omega}$ was obtained, corresponding to a normalized power factor of $4.1{\mu}W/(G^2{\cdot}cm^3)$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.30-30
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• 2008

Lead-free piezoelectric ceramics 0.97$(Na_{0.5}K_{0.5})NbO_3$-0.03Ba$(Ti_{1-x}Sn_x)O_3$ [NKN-BTS-x] ceramics doped with 1 mol% $MnO_2$ have been fabricated by a sintering technique with muffling. The $MnO_2$-doped NKN-BTS-x ceramics with x$\leq$0.2 have pure orthorhombic perovskite structure at room temperature. The dense microstructure was developed with grain growth as an increase of amount of Sn. Moreover, the addition of Sn was found to have a significant influence on piezoelectric properties. In particular, the $MnO_2$-doped NKN-BTS-0.1 ceramics showed improved piezoelectric properties of piezoelectric constant ($d_{33}$=145pC/N), relatively large electromechanical coupling factor ($k_p$=43%), dielectic constant (${\varepsilon}^T_{33}/{\varepsilon}_0$=676) dielectric loss (tan$\delta$=1.3%).

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.11a
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• pp.190-191
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• 2006

본 연구에서는 압전 세라믹을 이용한 Piezoelectric Energy Harvesting Systems을 개발하기 위해서, 바이몰프 액츄에이터를 제작하여 구동속도에 따른 발전특성을 고찰하였다. 또한 발전 회로시스템을 설계하여 압전소자에 의한 발전특성을 분석하였다. 본 시스템을 통해서 에 1.3 mm(100 V 인가)의 대변위 바이몰프 액츄에이터를 제작하였으며, 이런 액츄에이터를 이용하여 60 mW급의 LED를 구동하였다.

• Transactions on Electrical and Electronic Materials
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• v.18 no.3
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• pp.144-147
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• 2017

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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.579-580
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• 2014

In this research, modeling and analysis of an ultrasonic transducer composed of single crystal piezoelectric material(PMN-28PT) are conducted with FEM in reference with that composed of piezoelectric ceramic(PZT-4). Acoustic performances of the ultrasonic transducer are compared with magnitude, phase of impedance and trasmitting voltage response according to the type of piezoelectric materials.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.6
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• pp.420-425
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• 2012

Lead-free piezoelectric ceramic/epoxy composites with '0-3' connectivity were prepared by cold-pressing with a temperature controlled curing method. A ceramic powder with a composition of $(Na_{0.51}K_{0.47}Li_{0.02})(Nb_{0.8}Ta_{0.2})O_3$ was synthesized by a conventional solid state reaction route. The dielectric and piezoelectric properties of ceramic/epoxy composites were characterized as a function of the volume fraction (${\phi}$) of piezoelectric ceramics, which was varied from 70 to 95 vol%. The results indicated that the piezoelectric properties of composites were significantly affected by the volume fraction of ceramics. In terms of the piezoelectric properties, specimens showed the best performance at ${\phi}$= 85 vol%, resulting in the piezoelectric constant $d_{33}$ of 39 pC/N and the figure of merit as a piezoelectric energy harvester ($d_{33}{\cdot}g_{33}$) of 1.24 $pm^2/N$.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.2
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• pp.84-89
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• 2016

We present the results of a study of a piezoelectric generator that generates electricity by the application of tension to an element. A device is named "EYE-type generator". The EYE-type generator consists of a rectangular ceramic and two elastic body plates that are attached to upper and lower surfaces of a ceramic. If tension is applied to both ends of the elastic body, that tension is transformed to pressure on the ceramic through a change in the form of the elastic body, causing a piezoelectric effect whereby electricity is generated by the ceramic. This generator is relatively durable because a forces are not applied directly to the ceramic. We examined dependencies of the generator's output characteristics on the size of the ceramic and elastic body. A resonance and output characteristics were analyzed by using a finite element method. The generator was fabricated based on results of the analysis, and this was attached to a frequency-controllable vibrator to measure the output characteristics. The measured results were compared with results of the simulation, and the results pointed to the practicality of the design.