• Journal of Electrochemical Science and Technology
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• v.4 no.4
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• pp.125-139
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• 2013

The electrical conductive polymers (ECPs) reported at my research group are introduced in this review, which works are started from the late Professor Su-Moon Park's pioneering research for polyaniline at the University of New Mexico. The electrochemical and spectroelectrochemical properties and their applications to sensor and energy conversion systems are briefly described. At first, the growth and degradation mechanism of polyaniline describes and we extend to polypyrrole, polyazulene, polydiaminonaphthalenes, and polyterthiophene derivatives. In addition, the preparation of monomer precursors having functional groups is briefly described that can give us many exceptional applications for several chemical reactions. We describe the application of these ECPs for the fabrication of chemical sensors, biosensors, biofuel cells, and solar cells.

• Journal of Sensor Science and Technology
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• v.26 no.6
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• pp.397-401
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• 2017

A DC resistance type humidity sensor using conductive carbon ink was fabricated and its performance was evaluated. The humidity sensor was fabricated using a screen printing technique and have a structure that does not require additional metal electrodes to measure resistance change. To evaluate the performance of the humidity sensor, we measured the DC resistance change under various relative humidity levels. The fabricated humidity sensor showed a resistance change of about $2.5{\sim}50k{\Omega}$ in 11 ~ 95% RH environment. It also shows a linear relationship in the relative humidity versus log DC resistance graph. In comparison with commercial humidity sensor under real environment, it can be confirmed that the resistance of the humidity sensor changes to almost the same level as the measured humidity. These results show that the resistance type humidity sensor can be operated stably in actual environment.

• Journal of the Korean Ceramic Society
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• v.50 no.5
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• pp.309-318
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• 2013

Graphene has attracted considerable attention since its first production from graphite in 2004, due to its outstanding physical and chemical properties. The development of production methodsfor large scale, high quality graphene films is an essentialstep toward realizing graphene applications such as transparent, conductive film. Chemical deposition methods, using metal catalystsand gaseous carbon sources, have been extensively developed for large area synthesis. In this paper, wereview recent progress ingraphene production, and survey the role of graphene electrodes in various electronic devices such as touch panels, solar cells, solid statelighting and microelectronic devices.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.2
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• pp.75-80
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• 2008

The fabrication of complex three-dimensional electrodes for micro electrical discharge machining (micro-EDM) is an important issue in the field of micromachining Localized electrochemical deposition (LECD) is a simple and inexpensive technique for fabricating micro-EDM electrodes. This study presents a new process for manufacturing electrodes with complex cross-sections using masks of different shapes, In this process, a non-conductive mask is placed between an anode and cathode that are immersed in a plating solution of acidified copper sulfate. The LECD is achieved by applying a pulsed voltage between the anode and cathode, which are separated by a small distance. In this setup, the cathode is placed above the anode and the mask, so that the deposited electrode can be used directly for EDM without changing the tool orientation. We found that the microstructure of the deposited electrode is influenced by the concentration of the plating solution and organic additives. Moreover, the values of the voltage, frequency, and duty cycle of the pulsed input have significant effects on the microstructure of the fabricated electrode. Finally, the optimum values of the voltage, frequency, and duty cycle were determined for the most effective fabrication of complex-shaped electrodes.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.2
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• pp.115-120
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• 2021

In this study, composite transparent electrodes were fabricated either from a conductive polymer poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) or silver nanowire (AgNW). Three transparent electrodes such as PEDOT:PSS, PEDOT:PSS and AgNW mixture, and AgNW were fabricated. As for a transparent electrode, measured sheet resistance values were 89.6, 60.6 and 28.6 Ω/sq, and the transmittance values were 80.2, 82.0 and 83.8% while surface roughness (Rq) values were 4.1, 8.1, 20.4 nm for PEDOT:PSS, PEDOT:PSS and AgNW mixture, and AgNW, respectively. To verify the overall performance of these composite electrodes, we applied these electrodes to the top electrode of the solution-processed organic solar cells (OSCs). PEDOT:PSS provided the best performance with a fill factor (FF) of 51.2% and a photoconversion efficiency (PCE) of 2.2%, while traditional metal top electrode OSC provided FF of 60.5% and PCE of 3.1%.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.3
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• pp.427-440
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• 2020

This study developed a vest prototype capable of monitoring body temperature using textile electrodes to prevent the sudden death of babies as well as to determine the quality of developed products by evaluating usability with commercial products. Based on the results of the 7th Size Korea Project, a basic pattern for a vest prototype was drafted by applying the average size of two-year-old Korean babies. Two prototypes were the detachable (VEST I) and integrated textile electrodes vest type (VEST II), which followed the same design. The materials were 100% cotton single jersey (SJ) and double jersey (DJ). Six experts evaluated the usability of the developed vests (VEST I & VEST II) and commercial product (VEST M). The single-layer woven textile electrode appeared to have a slightly higher conductivity than the double-layer one. There was no statistical difference in the body temperature sensing function between VEST I and VEST II. Finally, the superiority of the VEST I was verified through a comparison with commercial products (VEST M). The usability test suggested that a wearable smart clothing system of the integrated conductive textile could be further commercialized for bio-monitor applications in Ubiquitous-health care.

• Bulletin of the Korean Chemical Society
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• v.32 no.2
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• pp.571-575
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• 2011

Graphite-based electrodes were prepared using synthetic graphite (MCMB 1028) or natural graphite (NG) powder using a dimensionally stable anode (DSA) as a substrate. Their electrochemical properties were investigated in vanadiumbased electrolytes to determine how to increase the durability and improve the energy efficiency of redox flow batteries. Cyclic voltammetry (CV) was performed in the voltage range of -0.7 V to 1.6 V vs. SCE at various scan rates to analyze the vanadium redox reaction. The graphite-based electrodes showed a fast redox reaction and good reversibility in a highly concentrated acidic electrolyte. The increased electrochemical activity of the NG-based electrode for the $V^{4+}/V^{5+}$ redox reaction can be attributed to the increased surface concentration of functional groups from the addition of conductive material that served as a catalyst. Therefore, it is expected that this electrode can be used to increase the power density and energy density of redox flow batteries.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.107-108
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• 2000

We propose the method which is possible to fabricate the electrodes with the fine pattern and low resistance by photolithography and electroplating. The widths of pattern fabricated were 30, 50, 70 and 100um and the thickness could be up to $10{\mu}m$. The resistivity of the copper electrode electroplated was below $2.0{\mu}{\Omega}$ cm which is about half of photosensitive silver electrode. Dielectric layer was coated on the electrodes by screen printing and the pores harmful to the discharge were not formed after heat treatment. In the viewpoint of resistance and patterning, this method has much higher potential for large area display than other methods like screen printing, photosensitive conductive paste method and sputtering.

• Proceedings of the KIEE Conference
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• 1999.07g
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• pp.3268-3270
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• 1999

This paper presents the fabrication of a micro electromagnetic flowmeter for liquid flow rate measurement. The flowmeter consists of a silicon flow channel with two electrodes and two permanent magnets. The micro flow channel and the detection electrodes are fabricated by the anisotropic etching of two silicon substrates and the metal evaporation process respectively. If conductive fluid passes through a magnet field, electromotive force is generated and detected by two electrodes. When the flow rate is 2.6 ml/sec, the measured output voltage is 7.4 mV.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.46.5-46
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• 2001

Electrostrictive polymer is deformed by electric force generated by electric field built by high voltage. When high voltage is applied to the electrostrictive polymer film in which the electrodes such as conductive grease or carbon powder are installed, it expands in the direction of area. Because electrostrictive polymer is incompressible and electric force is applied to it in the direction of thickness. Electrostrictive polymer film in which electrodes are installed, functions as a parallel-plate capacitor. Therefore anode and cathode charges are piled up or both electrodes and there exists attractive force that functions as pressure in the direction of thickness. So the thickness of electrostrictive polymer becomes thicker ...