• 한국조명전기설비학회지:조명전기설비
• /
• 제1권2호
• /
• pp.62-69
• /
• 1987

이 논문은 Phenolic 수지의 Tracking파괴의 CTI에 관한 고찰로써 전극재료의 일부가 누설재료에 의하여 침식되기 때문에 tracking파괴를 증진시키며 다음과 같은 영향을 받는다. $\circled1$절연재료에서는 C. T. I의 값이 350정도에서는 현재까지 규정하고 있는 백금전극보다도 황동전극이 더욱 근사한 값을 얻을 수 있었다. $\circled2$C. T. I의 값은 전해액의 저항율과는 무관하다. $\circled3$시요표면의 접촉각이 증가함에 따라 Corona 개시전압과 C. T. I의 값은 증가한다.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 하계학술대회 논문집 Vol.3 No.2
• /
• pp.723-726
• /
• 2002

We give pressure stimulation into organic thin films and then manufacture a device under the accumulation condition that the state surface pressure is 10[mN/m]. In processing of a device manufacture, we can see the process is good from the change of a surface pressure for organic thin films and transfer ratio of area per molecule. The structure of manufactured device is Au/Poly-$\gamma$ Benzyl $_D$-Glutamate/Al; the number of accumulated layers is 1, 3, 5 and 7. Also, we then examined of the MIM device by means of I-V. The I-V characteristic of the device is measured from 0 to +2[V]. We determined electrochemical measurement by using cyclic voltammetry with a three-electrode system. LB film accumulated by monolayer on an ITO. In the cyclicvoltammetry, An Ag/AgCl reference electrode, a platinum wire counter electrode and LB film-coated ITO working electrode measured in $LiBF_4$ solution, stable up to 0.9V vs. Ag/AgCl.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2002년도 하계학술대회 논문집
• /
• pp.354-357
• /
• 2002

Thermally grown gate oxide on 4H-SiC wafer was investigated. The oxide layers were grown at l150$^{\circ}C$ varying the carrier gas and post activation annealing conditions. Capacitance-Voltage(C-V) characteristic curves were obtained and compared using various gate electrode such as Al, Ni and poly-Si. The interface trap density can be reduced by using post oxidation annealing process in Ar atmosphere. All of the samples which were not performed a post oxidation annealing process show negative oxide effective charge. The negative oxide effective charges may come from oxygen radical. After the post oxidation annealing, the oxygen radicals fixed and the effective oxide charge become positive. The effective oxide charge is negative even in the annealed sample when we use poly silicon gate. Poly silicon layer was dope by POCl$_3$ process. The oxide layer may be affected by P ions in poly silicon layer due to the high temperature of the POCl$_3$ doping process.

• 한국수소및신에너지학회논문집
• /
• 제12권3호
• /
• pp.231-238
• /
• 2001

Electrocatalytic activity of palladium for hydrogen oxidation and reduction was studied using AC impedance method. The system under study was arranged in electrolytic mode consisting of Pd electrode under study, Pt counter electrode and Nafion electrolyte between them. Two types of Pd electrodes were used - carbon-supported Pd (Pd/C) and Pd foil electrode. Pd/C anode contacting pure hydrogen showed a steady decrease of charge transfer resistance with the increase of anodic overpotential, which is an opposite trend to that found with Pd foil anode. But Pd foil cathode also exhibited a decrease of the resistance with the increase of cathodic overpotential. The relationship between imposition of overpotential and subsequent change of the charge transfer resistance is determined by the ratio of the rate of faradaic process to the rate of mass transportation; if mass transfer limitation holds, increase of overpotential accompanies the increase of charge transfer resistance. Regardless of the physical type of Pd electrode, the anode contacting hydrogen/oxygen gas mixture did not reveal any independent arc originated from local anodic oxygen reduction.

• 대한의용생체공학회:의공학회지
• /
• 제32권3호
• /
• pp.207-217
• /
• 2011

Electrode impedances are measured to quantitatively characterize the electrode-electrolyte or cell-electrode interfaces. In the case of high-density microelectrode arrays(MEAs) that have been developed for brainmachine interface applications, the characterization process becomes a repeating and time-consuming task; a system that can perform the measurement and analysis in an automated fashion with accuracy and speed is required. However, due to the large number of channels, parasitic capacitance and off-capacitance components of the switching system become the major factors that decreased the accuracy for the measurement of high impedance microelectrodes. Here we investigated the implementation of automatic impedance measurement system with analyzing the causes of possible measurement-related problems in multichannel switching configuration. Based on our multi-channel measurement circuit model, we suggest solutions to the problems and introduce a novel impedance measurement scheme using electro-mechanical relays. The implemented measurement system could measure |Z| < 700 $k{\Omega}$ of impedance in - 10% errors, which can be widely applicable to high density neural recording MEAs.

• Smart Structures and Systems
• /
• 제14권2호
• /
• pp.247-266
• /
• 2014

Conventional cantilevered piezoelectric energy harvesters (PEHs) are usually fabricated with continuous electrode configuration (CEC), which suffers from the electrical cancellation at higher vibration modes. Though previous research pointed out that the segmented electrode configuration (SEC) can address this issue, a comprehensive evaluation of the PEH with SEC has yet been reported. With the consideration of delivering power to a common load, the AC outputs from all segmented electrode pairs should be rectified to DC outputs separately. In such case, theoretical formulation for power estimation becomes challenging. This paper proposes a method based on equivalent circuit model (ECM) and circuit simulation to evaluate the performance of the PEH with SEC. First, the parameters of the multi-mode ECM are identified from theoretical analysis. The ECM is then established in SPICE software and validated by the theoretical model and finite element method (FEM) with resistive loads. Subsequently, the optimal performances with SEC and CEC are compared considering the practical DC interface circuit. A comprehensive evaluation of the advantageous performance with SEC is provided for the first time. The results demonstrate the feasibility of using SEC as a simple and effective means to improve the performance of a cantilevered PEH at a higher mode.

• Current Photovoltaic Research
• /
• 제11권1호
• /
• pp.13-17
• /
• 2023

Functional transparent electrode was achieved by metal oxide-metal-Metal oxide (OMO) structure. Tailoring of metal oxide and metal layers, optically transparent and electrically excellent OMO films were investigated. Silver (Ag) is adopted for the metal layer and Ag oxide (AgO) is reactively formed by flowing O₂ gas during the sputtering process. This spontaneous AgO formation from Ag simultaneously provides the good electrical interface with high transparency. Due to the feature of transparent electrode of OMO, it endows the shielding effect (SE) function of electromagnetic interference. Optically transparent and electrically conductive OMO electrode shows the high transmittance (83.7%) and low sheet resistance (6.5 Ω/☐) with SE of 29.54 dB.

• 센서학회지
• /
• 제32권6호
• /
• pp.432-440
• /
• 2023

This study introduces an efficient readout circuit designed for two-electrode electrocardiogram (ECG) recording, characterized by its low-noise and low-power consumption attributes. Unlike its three-electrode counterpart, the two-electrode ECG is susceptible to common-mode interference (CMI), causing signal distortion. To counter this, the proposed circuit integrates a common-mode charge pump (CMCP) with a window comparator, allowing for a CMI tolerance of up to 20 V_PP. The CMCP design prevents the activation of electrostatic discharge (ESD) diodes and becomes operational only when CMI surpasses the predetermined range set by the window comparator. This ensures power efficiency and minimizes intermodulation distortion (IMD) arising from switching noise. To maintain ECG signal accuracy, the circuit employs a chopper-stabilized instrumentation amplifier (IA) for low-noise attributes, and to achieve high input impedance, it incorporates a floating high-pass filter (HPF) and a current-feedback instrumentation amplifier (CFIA). This comprehensive design integrates various components, including a QRS peak detector and serial peripheral interface (SPI), into a single 0.18-㎛ CMOS chip occupying 0.54 mm². Experimental evaluations showed a 0.59 µV_RMS noise level within a 1-100 Hz bandwidth and a power draw of 23.83 µW at 1.8 V.

• 한국재료학회지
• /
• 제1권4호
• /
• pp.229-235
• /
• 1991

$Ta_2O_5$ 박막은 실리콘산화막, 실리콘질화막 박막에 비해 유전율은 높으나 누설전류밀도가 높고, 절연파괴강도가 낮아 DRAM의 커패시터용 재료로서 실용화가 되지 못하고 있다. 본 연구에서는 LPCVD법으로 형성시킨 $300{\AA}$ 두께의 $Ta_2O_5$ 유전체박막에 대해 후속열처리 또는 전극재료를 변화시켜 열악한 전기적 특성의 원인을 규명하고자 하였다. 그 결과 다결정 실리콘 전극의 경우 성막상태의 $Ta_2O_5$ 박막은 전극에 의한 환원반응에 의해 전기적 특성이 열화됨을 알 수 있었고, 이를 TiN 전극의 사용으로 억제시킬 수 있었다. 다결정 실리콘 전극의 경우 성막상태의 $Ta_2O_5$ 유전체는 누설정류밀도가 $10^{-1}A/cm^2$, 절연파괴강도가 1.5MV/cm 정도였으며, $800^{\circ}C$에서 $O_2$열처리를 하면 전기적 특성은 개선되나, 유전율이 낮아진다 TiN 전극을 채용할 경우 누설전류밀도 $10^{-6}~10^{-7}A/cm^2$, 절연파괴강도 7~12MV/cm 로 ONO(Oxide-Nitride-Oxide) 박막과 비슷한 $Ta_2O_5$ 고유전막을 얻을 수 있었다.

• 전기화학회지
• /
• 제2권2호
• /
• pp.70-74
• /
• 1999

위상이동 방법을 이용하여 Pd/0.5 M LiOH전해질 계면의 전극속도론적 패러미터를 정성적으로 해석하였다. 위상이동$(\phi)$은 음전위(E<0) 주파수(f)에 따르며, Pd음극에 흡착된 수소원자$(H_{ads})$의 표면피복율$(\theta)$ 반비례한다. 중간주파수 (10 Hz)에서 위상이동 변화$(\phi\;vs.\;E)$는 Frumkin흡착등온식$(\theta\;vs.\;E)$의 계산 및 도시에 사용할 수 있는 실험적인 방법이다. Pd/0.5 M LiOH전해질 계면에서 $1>{\theta}>0$에 따른 흡착자유에너지변화율(r),흡착평형상수(K),표준자유에너지$({\Delta}G_{\theta})$는 각각 22.3kJ/mol, $3.7\times10^{-3}{\Delta}G_{\theta}>-8.4kJ/mol$이다. 1$0.38>\theta>0$ 범위에서 수소원자 흡수에 기인한 에너지 방출 즉 발열반응이 Pd음극에서 있다. 전극속도론적 패러미터$(r,\;K,\;{\Delta}G_{\theta}$는 표면피복율$({\theta})$ 또는 위상이동$(\phi)$에 따른다.