• Title, Summary, Keyword: Metal electrode

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A Study on the Electronic Properties of Organic Thin Films that Manufacture by LB Method (LB법으로 제작한 유기박막의 전자이동특성에 관한 연구)

  • Song, Jin-Won;Kim, Young-Keun;Lee, Kyung-Sup
    • Proceedings of the KIEE Conference
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    • pp.1539-1541
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    • 2002
  • When did Metal (Au, Al) electrode differently, it is spread already that it is by energy level of electrode difference of electrical conductivity. This paper, experiment manufactures device of Metal/Organic Films/Metal structure using PBDG and I-V properties by electrode analyzed comparison. Also, measure energy level by electrode by propertiesy electrochemistry and studied about electron transfer of organic thin film in LUMO level relation with HOMO level.

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Influence of Electrical Conductivity of Dielectric on Machinability of W-EDM (방전액의 전도율이 와이어방전가공성에 미치는 영향)

  • Kim, Chang-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.2
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    • pp.322-328
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    • 2002
  • In wire-electrical discharge machining (W-EDM), the dielectric plays an important role as the working fluid. It affects the material removal rate and the properties of the machined surface. This paper deals with the effects of the electrical conductivity of dielectric and cobalt percentage of sintered carbides on the machining characteristics and the machined surface integrities with deionized water as dielectric. A series of experiments have been performed on sintered carbides having different cobalt contents. Experimental results show that a higher cobalt content of WC decreases the metal removal rate and worsens the surface quality. Lower electrical conductivity of the dielectric results in a higher metal removal rate as the gap between wire electrode and workpiece reduced. Especially, the surface integrities of rough-cut workpiece, wire electrode, and debris were analyzed also through scanning electron microscopy(SEM) and surface roughness tester. By energy dispersive spectrometry(EDS), it is confirmed that micro cracks and some of electrode material are found on the workpiece surface.

Potential Profiles and Capacitances of an Ideally Polarizable Electrode in a point Charged Electrolyte

  • Sang youl Kim;K. Vedam
    • Bulletin of the Korean Chemical Society
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    • v.10 no.6
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    • pp.585-591
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    • 1989
  • The effects of the charged metal on the overall electrostatic potential profiles and the capacitances of the electrical double layer are brought out. A model with a simplified jellium and a point-charged electrolyte is utilized in the present calculations. Electrons are assumed not to penetrate electrode surface due to a strong screening of electrolyte at the interface. Electron density functions and ion density functions are obtained, which are also based upon the Poisson equation and Boltzmann equation on either side of the interface. A complete potential profile starting from bulk electrode and ending at bulk electrolyte is obtained by connecting the two potential profiles (one inside the metal electrode, the other inside the electrolyte) with proper boundary conditions. In spite of the simplicity of the model, the present model reveals the importance of the effect of the charged metal on the electrostatic potential profile and the electrical double layer capacitances. The results are discussed and compared with the predictions by Gouy Chapman theory.

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Study of contact resistance using the transmission line method (TLM) pattern for metal of electrode (Cr/Ag & Ni) (TLM pattern을 사용한 Cr/Ag 및 Ni 전극에 따른 접합 저항 연구)

  • Hwang, Min-Young;Koo, Ki-Mo;Koo, Sun-Woo;Oh, Gyu-Jin;Koo, Sang-Mo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.349-349
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    • 2010
  • Great performance of many semiconductor devices requirs the use of low-resistance ohmic contact. Typically, transmission line method (TLM) patterns are used to measure the specific contact resistance between silicon and metal. In this works, we investigate contact resistance for metal dependent (Cr/Ag, Ni) using TLM pattern based on silicon-on-insulator (SOI) wafer. The electrode with Ni linearly increases contact resistance as the pattern distance increase from $15{\mu}m$ to $75{\mu}m$ in accumulation part, but non-linearly increase in inversion part. In additional, the electrode with Cr/Ag linearly increases contact resistance as the pattern distance increase from $15{\mu}m$ to $75{\mu}m$ in inversion part, but non-linearly increase in accumulation part.

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Detection of Trace Copper Metal at Carbon Nanotube Based Electrodes Using Squarewave Anodic Stripping Voltammetry

  • Choi, Changkun;Jeong, Youngsam;Kwon, Yongchai
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.801-809
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    • 2013
  • We investigate sensitivity and limit of detection (LOD) of trace copper (Cu) metal using pristine carbon nanotube (CNT) and acidified CNT (ACNT) electrodes. Squarewave based anodic stripping voltammetry (SWASV) is used to determine the stripped Cu concentration. Prior to performing the SWASV measurements, its optimal conditions are determined and with that, effects of potential scan rate and $Cu^{2+}$ concentration on stripping current are evaluated. The measurements indicate that (1) ACNT electrode shows better results than CNT electrode and (2) stripping is controlled by surface reaction. In the given $Cu^{2+}$ concentration range of 25-150 ppb, peak stripping current has linearity with $Cu^{2+}$ concentration. Quantitatively, sensitivity and LOD of Cu in ACNT electrode are 9.36 ${\mu}A\;{\mu}M^{-1}$ and 3 ppb, while their values are 3.99 ${\mu}A\;{\mu}M^{-1}$ and 3 ppb with CNT electrode. We evaluate the effect of three different water solutions (deionized water, tap water and river water) on stripping current and the confirm types of water don't affect the sensitivity of Cu. It turns out by optical inspection and cyclic voltammetry that superiority of ACNT electrode to CNT electrode is attributed to exfoliation of CNT bundles and improved interfacial adhesion occurring during oxidation of CNTs.

Development of Discharge Electrode for Machining Connector Mold applying MIM Process (MIM 공법 적용 커넥터 금형 가공용 방전 전극 개발)

  • Shin, Kwang-Ho;Jeon, Yong-Jun;Heo, Young-Moo
    • Journal of the Korea Society of Die & Mold Engineering
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    • v.8 no.2
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    • pp.37-40
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    • 2014
  • A discharge electrode plays a role of shaving off workpiece with spark generated by current in discharge machining. Accordingly, for the discharge electrode, an electrode with excellent wear resistance is necessary. Generally, Graphite and Cu are used as the materials of the electrode, and recently Cu-W is mainly used as an electrode with excellent wear resistance. However, the form of the electrode generally used is produced mostly using cutting work, so a lot of costs incur if several similar forms are needed. Thus, this study developed a Cu-W electrode using Metal Injection Molding (MIM) process to produce similar forms with excellent productivity and a great quantity of electrodes in a similar form in discharge machining and carried out a discharge machining test. In developing an electrode applying MIM, predicting contraction of a product in a sintering process, a mold expansion ratio of 1.29486 was given, but the actual product showed a percentage of contraction 24% to 32%, which showed a difference of 3% to 5%. In addition, to verify wear resistance of the discharge electrode, abrasion loss was measured after the discharge.

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Molecular Level Detection of Heavy Metal Ions Using Atomic Force Microscope (원자간인력현미경을 이용한 분자수준의 중금속 이온 검출)

  • Kim, Younghun;Kang, Sung Koo;Choi, Inhee;Lee, Jeongjin;Yi, Jongheop
    • Clean Technology
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    • v.11 no.2
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    • pp.69-74
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    • 2005
  • A metal ion detector with a submicron size electrode was fabricated by field-induced AFM oxidation. The square frame of the mesa pattern was functionalized by APTES for the metal ion detection, and the remaining portion was used as an electrode by the self-assembly of MPTMS for Au metal deposition. The conductance changed with the quantity of adsorbed copper ions, due to electron tunneling between the mobile and surface electrodes. The smaller electrode has a lower limit of detection due to the enhancement in electron tunneling through metal ions that are adsorbed between the conductive-tip (mobile) and the surface (fixed) electrode. This two-electrode system immobilized with different functional groups was successfully used in the selective adsorption and detection of target materials.

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Extracting Photosynthetic Electrons from Thylakoids on Micro Pillar Electrode

  • Ryu, DongHyun;Kim, Yong Jae;Ryu, WonHyoung
    • International Journal of Precision Engineering and Manufacturing-Green Technology
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    • v.5 no.5
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    • pp.631-636
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    • 2018
  • Extraction of photosynthetic currents from thylakoids was studied using micro pillar structured electrode. Thylakoids were isolated from spinach leaves, and the size and shape of thylakoids were estimated from scanning electron microscopy images. Based on the geometry information of thylakoids, micro pillar shaped electrode was designed and fabricated using metal-assisted chemical etching of silicon wafers. Influence of photovoltaic effect on the silicon-based micro pillar electrode was confirmed to be negligible. Photosynthetic currents were measured in a three-electrode setup with an electron mediator, potassium ferricyanide. Photosynthetic currents from micro pillar electrodes were enhanced compared with the currents from flat electrodes. This indicates the significance of the enhanced contact between thylakoids and an electrode for harvesting photosynthetic electrons.

The Effect of Ion Exchange Membrane on the Electrical Conduction in Metal Fuel Cell (금속연료전지에서 이온교환막이 전기전도에 미치는 영향)

  • Kim, Yong-Hyuk
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.12
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    • pp.2235-2239
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    • 2010
  • In this study, The cation exchange membrane and the anion exchange membrane affect in electrical conduction of metal fuel cell was investigated. Magnesium material as anode electrode and the NaCl solution dissolved with 5~15wt% as electrolyte were used for the metal fuel cell. It was found that magnesium slag where flows toward the air electrode was suppressed by using ion exchange membrane. The open circuit voltage variation during discharge has very flat pattern by using ion exchange membrane, but the case which is not the exchange membrane, the open circuit voltage increased according to time. When using the anion exchange membrane, the electric current was higher case of the cation exchange membrane, as a result of higher equivalent conductivity in anion Cl-. The cation exchange membrane was observed with the fact that the output power is excellent in compared with anion exchange membrane.

A Study on the Development of Underwater Wet Welding Electrodes

  • Kim, Min-Nam
    • International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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    • v.6 no.1
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    • pp.75-81
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    • 2003
  • Underwater wet arc welds were experimentally performed on the KR-RA steel plate as base metal by using four different types of flux coated electrodes: KT33, UWEE, UWCS, and TN20. UWEE, the individually designed flux coated underwater electrode, had good operability when compared with other domestic terrestrial electrodes, and imported goods. The hardness value and the portion of martensite of HAZ were increased, by using a rapid cooling rate, Mechanical properties were also examined experimentally with a multi-pass butt-welding specimen test. The individually designed flux coated electrode UWEE could be used in practice for underwater wet welds.

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