• Polymer(Korea)
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• v.35 no.4
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• pp.370-374
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• 2011

A conductive PANI solution was successfully fabricated by doping with camphorsulfonic acid and the polymerization of aniline and the confirmation of doping were characterized by FTIR spectroscopy. In organic thin film transistors, PANI gate electrodes were spin-coated on a PES substrate and their conductivity variations were monitored by a 4-probe method with different annealing temperatures. The surface properties of PANI thin films were investigated by an AFM and an optical microscope, OTFTs with PANI gate electrode had characteristics of carrier mobility as large as 0.15 $cm^2$/Vs and on/off ratio of $2.4{\times}10^6$, Au gate OTFTs with the same configuration were fabricated to investigate the effect of polymer gate electrode for the comparison of device performances. We could obtain the comparable performances of PANI devices to those of Au gate devices, resulting in an excellent alternative as an electrode in flexible OTFTs instead of an expensive Au electrode.

• Journal of the Semiconductor & Display Technology
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• v.22 no.3
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• pp.52-61
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• 2023

We designed a novel ultra-miniaturized microcolumn structure having an stigmator to significantly improve throughput per unit time, which is the biggest disadvantage of microcolumns. We adopted the structure of the stigmator in the form of an electrostatic octupole electrode, and used an electrostatic quadrupole deflector with a relatively simple structure considering the increase in wiring due to the introduction of the stigmator. We have dramatically reduced the effect of astigmatism that occurs when the electron beam probe is scanned to the periphery of the target by introducing the stigmator between the control electrode and the deflector. As our numerical analysis simulation results, the field of view obtained as a result of this study is about 46.3% improved compared to our previous study, and the electron beam probe size of less than 10 nm was achieved in the entire field of view.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.10
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• pp.1984-1991
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• 2011

Among ground impedance measurement methods, the fall-of-potential method is the most thorough and reliable method. In the fall-of-potential method, ground electrode and auxiliary probes are placed in a straight line, and then, auxiliary potential probe is moved away from the ground electrode. The point at which plotted resistance curve flattens out is taken as right position of auxiliary potential probe. However, in some cases, it is hard to place ground electrode and auxiliary probes in a straight line. Therefore, we provided alternative placement method in this research. The method can be easily applicable to placing auxiliary probes. Also, this paper analyzed and compared ground impedance measurement standards of large grounding systems. Based on the analysis, practical measurement method using an earth tester was proposed. The proposed methods presented in this paper will be useful when determining locations of auxiliary probes in alternative positions, and the methods can be applied practically and easily.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.327-327
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• 2011

A nonthermal bioplasma source was developed for application to human liquid fluids by making use of nano-size tungsten tips. Characteristics of the plasma source are investigated. Here we have used the AC voltage system. The bioplasma source generated by a tungsten tip with quartz tube and ground electrode is a low-temperature plasma without making any noticeable damage to cells at a low power operation. The breakdown voltage and current signals are measured by high voltage probe (Tektronix P6015A) and current probe (P6021). Variation of breakdown temperature near the tip electrode is larger than that in the neighborhood of ground electrode. Bubble formation during discharge has been recorded and investigated by using the high speed camera. The existence and behavior of hydroxyl and superoxide radicals are detected and measured by spectrometers. The electrical and optical properties of breakdown characteristics are also investigated.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.508-508
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• 2012

CST microwave studio is used to simulate the plasma profile of the 450mm CCP source. Standing wave effect becomes important at the high frequency as the electrode radius increases. To solve plasma non-uniformity problem, we designed multi electrode chamber to decreasing standing wave effect. Simulation showed the ratio of input power of each electrode is related with electric field strength. The multi electrode was constructed and measured by 2D probe arrays using floating harmonic method. Uniformity of 450 mm CCP was changed by the ratio of input power of each electrode. We described this dependence with circuit model.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.6 s.183
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• pp.166-173
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• 2006

In this study, a probe array has been developed for use in a data storage device that is based on scanning probe microscope (SPM) and MEMS technology. When recording data bits by poling the PZT thin layer and reading them by sensing its piezoresponse, commercial probes of which the tip heights are typically shorter than $3{\mu}m$ raise a problem due to the electrostatic forces occurring between the probe body and the bottom electrode of a medium. In order to reduce this undesirable effect, a poly-silicon probe with a high aspect-ratio tip was fabricated using a molding technique. Poly-silicon probes fabricated by the molding technique have several features. The tip can be protected during the subsequent fabrication processes and have a high aspect ratio. The tip radius can be as small as 15 nm because sharpening oxidation process is allowed. To drive the probe, electrostatic actuation mechanism was employed since the fabrication process and driving/sensing circuit is very simple. The natural frequency and DC sensitivity of a fabricated probe were measured to be 18.75 kHz and 16.7 nm/V, respectively. The step response characteristic was investigated as well. Overshoot behavior in the probe movement was hardly observed because of large squeeze film air damping forces. Therefore, the probe fabricated in this study is considered to be very useful in probe-based data storages since it can stably approach toward the medium and be more robust against external shock.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.4
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• pp.133-136
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• 2004

This research aims to develop a DNA chip array without an indicator. We fabricated a microelectrode array through photolithography technology. Several DNA probes were immobilized on an electrode. Then, target DNA was hybridized and measured electrochemically. Cyclic-voltammograms (CVs) showed a difference between the DNA probe and mismatched DNA in an anodic peak. This indicator-free DNA chip resulted in a sequence-specific detection of the target DNA.

• Electrical & Electronic Materials
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• v.11 no.11
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• pp.17-21
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• 1998

The surface potential distribution on insulating polymers was measured by scanning of the probe of an electrostatic voltmeter. The measurements were done for two measured by scanning of the probe of an electrostatis voltmeter. The measurements were done for two cases. In the first case, it was measured on the free surface of insulating films which had been inserted between plane electodes after the removal of the upper brass disk electrode. In the second case, we measured the charging region between a circular and its opposing concentric ring electrodes after the removal of dc ramp voltage in air and nitrogen gas.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.3C
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• pp.127-136
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• 2009

The objective of this study is the development and verification of the 4-electrode resistivity probe (4ERP) for the estimation of electrical properties of the saturated soils. The 4ERPs with wedge and plane types are manufactured to obtain the electrical resistivity without polarization at the electrodes by using Wenner array. The wedge type is for the penetration into the soil samples and the plane type is for the installation into the cells used for the laboratory tests. The consolidation tests are carried out by using 6 types of glass beads and 3 types of sands in size. The test results show that the electrical resistivity increases with a decrease in the porosity, and the constant m used in Archie's law is dependent on the particle shape rather particle size. The one dimensional liquefaction tests show that the porosity obtained by the 4ERP is similar to that determined by the volume fraction. The penetration of the 4ERP into the large scale calibration chamber produces the resistivity profiles. This study demonstrates that the 4ERP may effectively estimate the porosity of the saturated soils.

• Bulletin of the Korean Chemical Society
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• v.25 no.4
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• pp.577-580
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• 2004