• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.489-490
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• 2008

This paper describes the analysis of electric field distribution of high voltage polymeric bushing with structure. The high voltage bushing consists of FRP tube and housing made of LSR. The field control can be achieved by means of the design of such internal field shaper and top corona ring as grading electrodes. In accordance, the optimized design uses both internal and external elements for electric stress grading at critical parts of the bushing. Maxwell 2D simulator based on the boundary element method was also introduced in order to verify the reliability of the polymeric bushing.

• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.6
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• pp.270-275
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• 2005

In order for the application of the in-vivo endoscopic biopsy, a micromirror which can be driven at a low voltage is required. In this paper, a two-step micromirror composed of bottom electrodes, moving plate and top mirror plate is proposed. Because an electrical wiring of two plates are separated, they can be actuated separately. Therefore, an intermediate moving plate plays an important role in reducing the driving voltage in half. The designed device was fabricated by the surface micromachining. Maximum rotation angle of $6.3^{\circ}$ was obtained by applying DC 48V, while a conventional one-step mirror pulled down at DC 120V. The designed structure can be used in microphotonic applications requiring low driving voltage.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.474-475
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• 2007

The $Sr_{0.8}Bi_{2.2}Ta_2O_9$(SBT) thin films are deposited on Pt-coated electrode(Pt/$TiO_2/SiO_2$/Si) using RF magnetron sputtering method. The aging properties of SBT capacitor with top electrodes represents a favorable properties in Pt electrode. The dielectric constant and leakage current density with Pt electrode is 340 and $6.81{\times}10^{-10}\;A/cm^2$ respectively. The maximum remanent polarization and the coercive electric field with Pt electrode are $12.40{\mu}C/cm^2$ and 30kV/cm respectively.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.6
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• pp.687-693
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• 1998

This study was performed to examine the mean arterial pressure and nociceptive jaw opening reflex after microinjection of glutamate into the amygdala in freely moving rats, and to investigate the mechanisms of antinociceptive action of amygdala. Animals were anesthetized with pentobarbital sodium (40 mg/kg, ip). A stainless steel guide cannula (26 gauge) was implanted in the amygdala and lateral ventricle. Stimulating and recording electrodes were implanted into each of the incisor pulp and anterior digastric muscle. Electrodes were led subcutaneously to the miniature cranial connector sealed on the top of the skull with acrylic resin. After 48 hours of recovery from surgery, mean arterial pressure and digastric electromyogram (dEMG) were monitored in freely moving rats. Electrical shocks (200 ${\mu}sec$ duration, $0.5{\sim}2$ mA intensity) were delivered at 0.5 Hz to the dental pulp every 2 minutes. After injection of 0.35 M glutamate into the amygdala, mean arterial pressure was increased by $8{\pm}2$ mmHg and dEMG was suppressed to $71{\pm}5%$ of the control. Injection of 0.7 M glutamate elevated mean arterial pressure by $25{\pm}5$ mmHg and suppressed dEMG to $20{\pm}7%$ of the control. The suppression of dEMG were maintained for 30 minutes. Naloxone, an opioid receptor antagonist, inhibited the suppression of dEMG elicited by amygdaloid injection of glutamate from $28{\pm}4\;to\;68{\pm}5%$ of the control. Methysergide, a serotonin receptor antagonist, also inhibited the suppression of dEMG from $33{\pm}5\;to\;79{\pm}4%$ of the control. However, phentolamine, an ${\alpha}-adrenergic$ receptor antagonist, did not affect the suppression of dEMG. These results suggest that the amygdala can modulate both cardiovascular and nociceptive responses and that the antinociception of amygdala seems to be attributed to an augmentation of descending inhibitory influences on nociceptive pathways via serotonergic and opioid pathways.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.2
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• pp.309-314
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• 1997

The electrical properties of thick PZT films deposited on Ag-Pd/$Al_2O_3$ and Pt electrodes were carefully investigated according to the annealing methods and the sub-strates. For electrical properties measurements, silver was deposited on PZT films as top electrode. The crystallogaphic structure of the films was examined by standard X-ray diffraction method to determine which crystalline phase was present. Dielctric constant was measured at 1 kHz, 10 mV by using a HP4284A. The electrical properties of PZT films with 3 wt% PbO addition were not improved. It was also found that the Ag-Pd layer has a good possibility as electrode instead of Pt. It seems clear from the present experiments that the thick PZT films having the good electrical properties can certainly be obtained using spin on technique combined with rapid thermal annealing.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.482-483
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• 2011

Graphene is a good candidate for the future nano-electronic materials because it has excellent conductivity, mobility, transparency, flexibility and others. Until now, most graphene researches are focused on the nano electronic device applications, however, biological application of graphene has been relatively less reported. We have fabricated a deoxyribonucleic acid (DNA) conjugated graphene field-effect transistor (FET) and measured the electrical transport characteristics. We have used graphene sheets grown on Ni substrates by chemical vapour deposition. The Raman spectra of graphene sheets indicate high quality and only a few number of layers. The synthesized graphene is transferred on top of the substrate with pre-patterned electrodes by the floating-and-scooping method [1]. Then we applied adhesive tapes on the surface of the graphene to define graphene flakes of a few micron sizes near the electrodes. The current-voltage characteristic of the graphene layer before stripping shows linear zero gate bias conductance and no gate operation. After stripping, the zero gate bias conductance of the device is reduced and clear gate operation is observed. The change of FET characteristics before and after stripping is due to the formation of a micron size graphene flake. After combined with 30 base pairs single-stranded poly(dT) DNA molecules, the conductance and gate operation of the graphene flake FETs become slightly smaller than that of the pristine ones. It is considered that DNA is to be stably binding to the graphene layer due to the ${\pi}-{\pi}$ stacking interaction between nucleic bases and the surface of graphene. And this binding can modulate the electrical transport properties of graphene FETs. We also calculate the field-effect mobility of pristine and DNA conjugated graphene FET devices.

• Journal of Sensor Science and Technology
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• v.5 no.1
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• pp.1-8
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• 1996

High-sensitive pyroelectric infrared sensors have been fabricated with La-modified $PbTiO_{3}$(PLT) thin plates. The PLT thin plates have the composition of $(Pb_{0.9}La_{0.1}Ti_{0.75}O_{3})_{0.75}(PbO)_{0.25}$. Thickness of the thin plates is $100\;{\mu}m$. Top side electrodes exposed to IR are vacuum evaporated Ni-Cr, and bottom side electrodes are Ag. Each one takes the area of $1{\times}2\;mm^{2}$. The thin plates have a large resistivity of $6.41{\times}10^{10}{\Omega}{\cdot}cm$ and a relative dielectric constant of 341. They have a high figure of merit of $4.0{\times}10^{-11}\;Ccm/J$ due to its high pyroelectric coefficient of $4.45{\times}10^{-8}\;C/cm^{2}K$. The sensors show such a large voltage responsivity as 2501 V/W. That they can find practical applications like the pyroelectric infrared detectors.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.3
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• pp.307-312
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• 1998

This study was performed to investigate the mechanism of central analgesic effects of antidepressants. Thirty four male rats were anesthetized with pentobarbital sodium (40 mg/kg, ip). A stainless steel guide cannula and a PE tube (PE10) were implanted into the lateral ventricle and cisterna magna area. Stimulating and recording electrodes were implanted into the incisor pulp and anterior digastric muscle. Electrodes were led subcutaneously to the miniature cranial connector sealed on the top of the skull with acrylic resin. The jaw opening reflex was used in freely moving rats, and antidepressants were administered intracisternally in order to eliminate the effects of anesthetic agents on the pain assessment and evaluate the importance of the central action site of antidepressants. After 48 hours of recovery from surgery, digastric electromyogram (dEMG) of freely moving rats was recorded. Electrical shocks (200 ${\mu}sec$ duration, 0.5-2 mA intensity) were delivered at 0.5 Hz to the dental pulp every 2 minute. Intracisternal administration of $15\;{\mu}g$ imipramine suppressed dEMG elicited by noxious electrical stimulation in the tooth pulp to $76{\pm}6%$ control. Intracisternal administration of $30\;{\mu}g$ desipramine, nortriptyline, or imipramine suppressed dEMG remarkably to $48{\pm}2,\;27{\pm}8,\;or\;25{\pm}5%$ of the control, respectively. Naloxone, methysergide, and phentolamine blocked the suppression of dEMG produced by intracisternal antidepressants from $23{\pm}2\;to\;69{\pm}4%,\;from\;32{\pm}5\;to\;80{\pm}9%,\;and\;from\;24{\pm}6\;to\;77{\pm}5%$ of the control, respectively. These results indicate that antidepressants produce antinociception through central mechanisms in the orofacial area. Antinociception of intracisternal antidepressants seems to be mediated by an augmentation of descending pain inhibitory influences on nociceptive pathways.

• Korean Journal of Materials Research
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• v.29 no.2
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• pp.87-91
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• 2019

We report on stretchable electrochromic films of poly(3-hexylthiophene) (P3HT) fabricated on silver nanowire (AgNW) electrodes. AgNWs electrodes are prepared on polydimethylsiloxane (PDMS) substrates using a spray coater for stretchable electrochromic applications. On top of the AgNW electrode, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is introduced to ensure a stable resistance over the electrode under broad strain range by effectively suppressing the protrusion of AgNWs from PDMS. This bilayer electrode exhibits a high performance as a stretchable substrate in terms of sheet resistance increment by a factor of 1.6, tensile strain change to 40 %, and stretching cycles to 100 cycles. Furthermore, P3HT film spin-coated on the bilayer electrode shows a stable electrochromic coloration within an applied voltage, with a color contrast of 28.6 %, response time of 4-5 sec, and a coloration efficiency of $91.0cm^2/C$. These findings indicate that AgNWs/PEDOT:PSS bilayer on PDMS substrate electrode is highly suitable for transparent and stretchable electrochromic devices.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.6
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• pp.9-14
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• 2011

We have investigated the electrical properties of $AlO_x$ thin film device. The device has been fabricated top-bottom electrode structure and its transport properties are measured in order to study the resistance change. Electrical properties with linear voltage sweep on a electrodes are used to show the variation of resistance of $AlO_x$ thin film device. Fabricated $AlO_x$ thin film device with MIM structure is changed from a high conductive On-state to a low conductive Off-state by the external linear voltage sweep. It is found that the initial resistance of the $AlO_x$ thin film is low-resistance On state and reversible switching occurs. Consequently, we believe $AlO_x$ thin film is a promising material for a next-generation nonvolatile memory and other electrical applications.