• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.250-254
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• 2000

High temperature superconducting films deposited on metal Ag wire were prepared with YBCO powders by electrophoretic deposition method. $I_2$was used as additives for surface charge of YBCO particles. When 2~3 wt.% $BaF_2$ was added in the YBCO suspension, the pores and cracks of film surface were decreased and film density could be increased. In case of YBCO films, the critical current density ($J_{c}$) was calculated at the value of $1458{\;}A/\textrm{cm}^2$ (77K, 0K) by 4 point prove method.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.2
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• pp.157-162
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• 2003

For fabricating high T$\sub$c/ superconducting deposition film, novel electrophoretic deposition (EPD) technique applied to deposit surface charged particles on metal substrate with only d.c field has been studied. However, the electric properties of superconducting film could not be improved easily by this way, because the particles of EPD film were usually deposited randomly on metal substrate without any directional orientation affected to its critical current density. For the purpose of obtaining partcle orientation on the EPD films, the new method modified by a.c. assisted field to the conventional electrophoresis system was investigated to improve the particle deposition density and to increase the contacting area among the particles with highly oriented particle deposition of BSCCO superconducting film.

• Journal of information and communication convergence engineering
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• v.1 no.1
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• pp.27-30
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• 2003

Electrophoretic deposition (EPD) of alcohol YBCO suspensions on the Ag wire electrode is studied. Poly(ethylene glycol) was coordinated to a structure formed by the EPD process with YBCO particles. The suspension is characterized in terms of zeta potential and conductivity. The d.c electric fields of 200-300 V/cm are applied for 1-10 min. The optimal condition for the EPD allows modifying the properties and microstructure of the deposited films. Superconducting coatings with nanometer-sized pores and a preferred orientation along the c-axis were prepared from the result with chemically modified precursor solution. In contrast, YBCO coatings of submicrometer-sized pores and randomly orientated grains were prepared from the solution without PEG.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.67-70
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• 1994

On this study, we fabricated humudity sensor with polyimide thin film from the nonaqueous emulsion by the electrophoretic deposition as a function of film thickness. then evaluated performance of the sensor with increasing relative humidity if constant temperature constant humidity chamber, which is electronically controlled. we designed upper electrode of the sensor to brush type to make moisture particles permeate into the polymer bulk. sensing properties of the sensor on % RH shows proportion on the low %RH. Fer the 30V-30S- 200$^{\circ}C$ sample, percentage changing of capacitance on from 30 %RH to 90 %RH is 45.8 %, and increasing rate per 1 % RH of capacitance is 11.25 pF

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.05a
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• pp.103-107
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• 1994

An experimental study was carried out to investigate the fabrication process and electrical breakdown of electrodeposted polyimide film from nonaqueous emulsion onto metal electrode surface. The thickness of imide film control led by the deposition voltage and time are proportional to the voltage or time. From the results, yeilds is proportional to the total elctrical charge flow through the electrode. When electrophoretic deposition voltage is 30 [V] deposition time is 30 sec, 40 sec, 50 sec, then the thickness of the films are 2.13 $\mu\textrm{m}$, 2.69 $\mu\textrm{m}$, 3.16 $\mu\textrm{m}$, 3.94 $\mu\textrm{m}$, respectively Electrical breakdown voltage of polyimide thin film shows very high. As film thicknes increase, the breakdown voltage are increased, but are net directly proprotional to thickness of the film.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.287-288
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• 2006

Two approaches for the fabrication of tailored powder composites with specially distributed pore-grain structure and chemical composition are investigated. Electrophoretic Deposition (EPD) followed by microwave sintering is employed to obtain functionally graded materials (FGM) by in-situ controlling the deposition bath suspension composition. $Al_2O_3/ZrO_2$ and zeolite FGM are successfully synthesized using this technique. In order to fabricate an aligned porous structure, unidirectional freezing followed by freeze drying and sintering is employed. By controlling the temperature gradient during freezing of powder slurry, a unidirectional ice-ceramic structure is obtained. The frozen specimen is then subjected to freeze drying to sublimate the ice. The obtained capillary-porous ceramic specimen is consolidated by sintering. The sintering of the graded structure is modeled by the continuum theory of sintering.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.687-690
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• 2004

The preparation of A1203-SiO2 thin films from less than one micron to several tens of microns in thickness had been Prepared from metal alkoxide sols. Two methods, dip-withdrawal and electrophoretic deposition, were employed for thin films and sheets formation. The requirements to be satisfied by the solution for preparing uniform and strong films and by the factors affecting thickness and other properties of the films were examined. For the preparation of thin, continuous A12O3-SiO2 films, therefore, metal-organic-derived precursor solutions contained Si and Al in a chemically polymerized form has been developed and produced in a clear liquid state.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.81-84
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• 1999

For the research of the effects on suspension solution with YBCO and BSCCO for elcectrophoretic deposition to prepare superconducting thick-film wire, it was investigated that the preheating technique for the superconducting powders in vacuum system was used with various solvent solutions of acetone, ethanol, toluene and buthanol for electrophoresis. As a result it was useful to remove the influence of remaining and adsorbed solvent solution which was existed between and on the particle surfaces when the specimens of superconducting wire by electrophoresis were treated in vacuum of 10$\^$-3/ Torr and temperature around 200$^{\circ}C$ in bell-jar system. From the prepared superconducting wire samples, the critical current density, Jc was measured by 4-point prove method in liquid N$_2$ at the value of 10$\^$3/ to 10$\^$4/ A/$\textrm{cm}^2$, respectively, for the YBCO and BSCCO superconducting wires.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.63-66
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• 2003

The electrophoretic deposition method has the advantage of relatively few fabrication facilities and simple process procedure as well as the economical and technical merit of allowing various forms of deposition and easy control of deposition thickness and wire length. A study, especially electric field and additive, on the optimization method to increase the density of particles and uniformity of their orientation have been performed to overcome the cracking and the porosity problems in the fabricated superconductor.

• Transactions on Electrical and Electronic Materials
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• v.17 no.4
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• pp.212-216
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• 2016

A reflective electronic display that uses negatively and positively charged particles has excellent bistability, a welldefined threshold voltage, and an extremely fast response time in comparison with other reflective displays. This type of display shows images through the movement of charged particles whose motion depends on the value of q/m (charge per mass for a particle). However, the ratio q/m can easily be changed by the forces acting on the charged particles in a cell of the panel and by friction that occurs after mixing oppositely charged particles and in the particle-insertion process. In this study, we propose a method to determine the appropriate range of q/m by using the reflectivity and response time of charged particles to modify q/m. In this manner, the electrical and optical properties of reflective displays are improved.