• Journal of Electrochemical Science and Technology
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• 제3권4호
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• pp.154-158
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• 2012

It is generally known that electrochemical impedance spectroscopy is a powerful technique and its real-time application has been demanded for prompt observations on instantaneous electrochemical changes. Nevertheless, long measurement time and laborious analysis procedures have hindered development of it. Solving the problems, here I report of a new algorithm design for development of a real-time electrochemical impedance monitoring system, which potentially provides a guideline in developing monitoring systems of electric vehicles batteries and other electrochemical power plants. The significant progress in this report is employment of the parallel processing protocol which connects independent sub functions to successfully operate with avoiding mutual interruptions. Therefore, all the processes required to monitor electrochemical impedance changes in realtime are properly operated. To realize the conceptual scheme, a Labview program was coded with sub functions units which conduct their processes individually and only data are transferred between them through the parallel pipelines. Finally, measured impedance spectra and analysis results are displayed, which are synchronized according to the time of change.

• 대한의용생체공학회:의공학회지
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• 제29권5호
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• pp.337-342
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• 2008

To date, many researchers have developed a variety of biosensors to detect the biomolecular interactions. Recently, electrochemical biosensors have been attracting great interest as one of key technologies in a ubiquitous healthcare (U-healthcare) system since they are highly sensitive and feasible to miniaturize. Here we overview the current electrochemical biosensors based on strip-type, nanowire/nanotube, field effect transistor (FET), and nanogap electrode.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.609-613
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• 2004

On this study, electrochemical polishing is adapted to ultra-fine surface for semiconductor large radius gas-tube. The system which buffing and electrochemical polishing can be performed simultaneously was constructed in connection with developing exclusive system. Based on existing papers and the research of background, electrode gap and electrolyte flow were fixed. Current density and electrochemical precision time were chosen as variables. On this study, it is objected to find optimal precision condition and precision variables on the in-process electrochemical polishing.

• 융복합기술연구소 논문집
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• 제2권2호
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• pp.25-29
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• 2012

Micro machining technologies have been required to satisfy various conditions in a high-technology industry. Micro electrochemical process is one of the most precision machining methods. Micro electrochemical process has been divided into electrochemical etching through protective layer and electrochemical machining using ultrashort voltage pulses. Micro shaft can be fabricated by electrochemical etching. The various protective layers such as photo-resist, oxide layer and oxidized recast layer have been used to protect metal surface during electrochemical etching. Micro patterning on metal surface can be machined by electrochemical etching through protective layer. Micro hole, groove and structures can be easily machined by electrochemical machining using ultrashort voltage pulses. Recently, the groove with subnanometer was machined using AFM.

• 전기학회논문지P
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• 제54권4호
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• pp.224-229
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• 2005

This paper presents a bidirectional pulse power electrochemical etching system for groove manufacturing of the dynamic bearings. To manufacture the dynamic bearing for the groove, it is very important to consider the depth and roughness. If the precision of the groove is not exact, we can not get the desirable performance for the target of the dynamic bearing. To make the groove of bearing precise, we propose the method of electrochemical etching system. In order to design the depth and roughness exactly, the bidirectional pulse power converter is proposed. With the bidirectional pulse power converter, we obtain the condition and the parameters of converter such as frequency, duty ratio, time, temperature, velocity, pressure and so on. In this paper, we get the experimental results to verify the precise groove manufacturing.

• International Journal of Precision Engineering and Manufacturing
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• 제8권4호
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• pp.27-32
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• 2007

Gears, crucial components in modern precision machinery for power transmission mechanisms, are required to have low contacting noise with high torque transmission, which makes the use of gear-tooth profile modifications and gear-tooth surface crowning extremely efficient and valuable. Due to the shortcomings of current techniques, such as manual rectification, mechanical modification, and numerically controlled rectification, we propose a novel electrochemical gear-tooth profile modification method based on an artificial neural network control technique. The fundamentals of electrochemical tooth-profile modifications based on real-time control and a mathematical model of the process are discussed in detail. Due to the complex and uncertain relationships among the machining parameters of electrochemical tooth-profile modification processes, we used an artificial neural network to determine the required processing electric current as the tooth-profile modification requirements were supplied. The system was implemented and a practical example was used to demonstrate that this technology is feasible and has potential applications in the production of precision machinery.

• Corrosion Science and Technology
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• 제9권6호
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• pp.331-337
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• 2010

This study compared the macro and micro electrochemical characteristics at the local area of welding metal on dissimilar welding parts for type 304 stainless steel (SS) and type 316L SS. The materials are used for double wall gas pipe of duel fuel engine for a ship. The various potentiodynamic experiments were performed several times in 10% ${H_2C_2O_2}{\cdot}{H_2O}$ solution using macro and micro methods, respectively. The micro electrochemical experiments conducted to resolve at local area on cross-section of dissimilar welding materials by micro-droplet cell device. The micro-droplet cell techniques can be used almost electrochemical experiments to resolve corrosion characteristics of the limited electrode area of the metallic surface between wetted spot of working electrode and tip of sharpened capillary tube. The results of macro electrochemical experiments show that resistance of active dissolution reaction at welding zone was high due to low current density by formation of passivation protection film at passive region. According to the micro electrochemical experiment, the corrosion current density of welding zone and bond zone were relatively high.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2000년도 추계학술대회 논문집
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• pp.906-909
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• 2000

To improve dimension accuracy and make very small parts are one of the major purpose on the electrochemical micromachining. This paper introduce a small machine tool by using the point electrode. That has a data acquisition system for gathering applied electric condition between the gap. Point electrode on this system was made by this method as well. It was found that variable phenomena occurred through the acquired V-I curve on the process.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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• pp.224-226
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• 2003

In this paper, we succeeded SNP discrimination of DNA hybridization on microarray using new electrochemical system. Using the electrochemical method with a label-free DNA has Performed DNA chip microarray. This method is based on redox of an electrochemical ligand. We developed scanning system with high performance.

• Journal of Electrochemical Science and Technology
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• 제9권4호
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• pp.301-307
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• 2018

The current study fabricated magnetic functional reduced graphene oxide (MFRGO) by relying on ${FeCl_4}^-$ magnetic anion confined to cationic 1-methyl imidazolium. Furthermore, for improving the electrochemical performance of conductive polymer, hybrid poly ortho aminophenol (POAP)/ MFRGO films have then been fabricated by POAP electropolymerization in the presence of MFRGO nanorods as active electrodes for electrochemical supercapacitors. Surface and electrochemical analyses have been used for characterization of MFRGO and POAP/ MFRGO composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. Prepared composite film exhibited a significantly high specific capacity, high rate capability and excellent cycling stability (capacitance retention of ~91% even after 1000 cycles). These results suggest that electrosynthesized composite films are a promising electrode material for energy storage applications in high-performance pseudocapacitors.