• Journal of Industrial Convergence
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• v.21 no.8
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• pp.35-42
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• 2023

Recently, electronic devices with bendable electronic devices based on flexible substrates are being sold, and therefore, the purpose of this study is to evaluate the possibility of flexible substrates of conductive transparent tapes. As a transparent electrode, carbon nanotube (CNT) was formed by the coating method developed by the research team, and samples coated up to 5 times were fabricated. The surface resistance and transmittance of the substrate were measured, and both resistance and transmittance decreased as the number of CNT coatings increased. After the tape was detached from the glass, the surface resistance slightly increased in all samples, and the transmittance increased by about 10% in all measured wavelength ranges because the glass was removed. Next, the tape coated with CNT twice was used to a bending test 20,000 times under the condition of a radius of curvature of 2 mm. The electrical and optical properties before and after bending did not change, which means that there was no change in CNT properties due to bending.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.8
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• pp.76-82
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• 2016

In this paper, we evaluated shielding effectiveness (SE) of carbon nanotube (CNT) film using near field scanning (NFS) in near field analysis. We adopted CNT film with deposit carbon density of 5% and thickness of 1mm for evaluation of shielding characteristic. Using a test coupon analogized to an actual IC package, we measured SE according to measuring position and SE according to distances between the CNT film and the test coupon. As a result, the measured SE in the near field varied with frequency. Especially, the measured electric field SE in the center of the test coupon is better than that of the measured edge point of the test coupon where it is affected by fringing effect. The results show that the measured SE in the near field is affected not only by frequency but also by measurement environment such as position and height of the probe and height of shielding film. In conclusion, we should choose proper methods for SE measurement considering interference distance in the electronic control system because there is little correlation between the proposed evaluation method in the near field and ASTM D 4935-10.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.3
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• pp.294-298
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• 2004

Carbon nanotubes(CNTs) were synthesized by thermal chemical vapor deposition(CVD) method. To fabricate CNT gas sensor, catalyst metal layer was deposited on microstructure. The CNT gas detecting layer was grown by thermal CVD method on the catalyst metal layer. In order to investigate the gas sensing characteristics of the fabricated CNT gas sensor, it was exposed in NO$_2$ gas and sensitivity, response, and recovery time were measured. As the result, this sensor has better reproductibility and faster recovery time than another CNT gas sensors.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1092-1095
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• 2005

The effect of the dielectric constant (${\varepsilon}$) of bonding materials in screen-printed carbon nanotube cathode on field enhancement factor was investigated using the ANSYS software for high-efficient CNT-cathodes. The field enhancement factor increased with decreasing the dielectric constant and reaching a maximum value when the dielectric constant is 1, the value for a vacuum. This indicates that the best bonding materials for screen-printing CNT cathodes should have a low dielectric constant and this can be used as criteria for selecting bonding materials for use in CNT pastes for high-efficient CNT-cathodes

• Applied Chemistry for Engineering
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• v.21 no.4
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• pp.430-434
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• 2010

The sheet for electromagenetic interference (EMI) shielding was prepared with slurry made by the mixture of binder, methyl ethyl ketone, cyclohexanone and metal powder. We tried to enhance the shielding efficiency by adding carbon nanotube (CNT), which has known as highly conducting material. Surface and component analyses were carried out with SEM and EDS, respectively. The electric characteristics and EMI shielding efficiencies were measured with 4-point probe measurement and EMI efficiency measurement equipment. The sheet with 2% CNT addition showed the lowest electrical resistance, $13.13{\Omega}}{\cdot}cm$. It also showed the highest EMI shielding efficiency of 63 dB.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.2
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• pp.99-107
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• 2015

This study was aimed to investigate the difference in strength of Carbon Nanotube (CNT) reinforced cement mortars with different types of surfactants and doses. In the experimental program, CTAB, SDBS and TX10 which were common surfactants adopted to improve CNTs dispersion in fabricating CNT composites in many industrial fields were included and superplasticizer which was revealed to be effective to disperse CNTs especially in CNT reinforced cementitious composites were added as well. Superplasticizer presented less strength reduction in cement mortar and more strength gain by adding CNTs among four types of surfactants. Higher dosage of superplasticizer caused lower strength of cement mortar. Adding CNTs of 0.4 wt.% or less to cement didn't show strength enhancement by adding CNTs but 0.8 wt.% of CNTs resulted in strengthening effect after all. Finally, a combination of 0.1 wt.% of CNTs, superplasticizer and sonication treatment could lead to strength improvement by adding CNTs in cement mortar.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.45 no.12
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• pp.8-14
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• 2008

A fully CMOS-integrated carbon nanotube (CNT) sensor array is proposed. After the sensor chip is fabricated in commercial CMOS process, the CNTs network is formed on the top of the fabricated sensor chip through the room-temperature post-CMOS processes. When the resistance of the CNT is changed by the chemical reaction, the read-out circuit in the chip measures the charging time of the $R_{CNT}$-Capacitor. finally the information of measured frequency is converted to a digital code. The CMOS sensor chip was fabricated by standard 0.18um technology and the size of the $8{\times}8$ sensor array is $2mm{\times}2mn$. We have carried out an experiment detecting the biochemical material, glutamate, using this sensor chip. From the experiment the CMOS sensor chip shows the feasibility of sensor for the simultaneous detection of the various target materials.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.6
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• pp.451-455
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• 2012

To compare an electrical and optical characteristics of indium tin oxide (ITO) and carbon nanotube (CNT) electrode on flexible and reflective display, we fabricate two charged particle-type display panels under the same panel condition of which the width of ribs is 10 ${\mu}m$, the cell size is $300{\mu}m{\times}300{\mu}m$, the q/m value of the white particles is -4.3 ${\mu}C/g$ and that for the black is +1.3 ${\mu}C/g$, and the cell gap is 75 ${\mu}m$, 125 ${\mu}m$, and 175 ${\mu}m$. We use plastic substrates coated with ITO and CNT electrode. To evaluate optical property, we measure a response time of particles using a laser and a photodiode. Threshold and driving voltages of CNT electrode according to the sheet resistance of 300, 600, 1,000 (ohm/sq) are compared with ITO electrode of 10 (ohm/sq). A response time of the CNT panel is similar to that of ITO panel, but the threshold and driving voltages of CNT panel are higher than that of ITO panel, inducing a large bombardment of the particles and shortening the lifetime of the panel. High difference of a threshold and a driving voltage of CNT panel will induce an particle clumping, resulting degradation of the panel. A bending radius of the fabricated CNT panel is 18 ${\mu}m$.

• Tribology and Lubricants
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• v.39 no.1
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• pp.8-12
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• 2023

This study presents a molecular simulation of adhesion control between carbon nanotube (CNT) and Ag thin film deposited on silicon substrate. Rough and flat Ag thin film models were prepared to investigate the effect of surface roughness on adhesion force. Heat treatment was applied to the models to modify the adhesion characteristics of the Ag/CNT interface based on thermal wetting. Simulation results showed that the heat treatment altered the Ag thin film morphology by thermal wetting, causing an increase in contact area of Ag/CNT interface and the adhesion force for both the flat and rough models changed. Despite the increase in contact area, the adhesion force of flat Ag/CNT interface decreased after the heat treatment because of plastic deformation of the Ag thin film. The result suggests that internal stress of the CNT induced by the substrate deformation contributes in reduction of adhesion. Contrarily, heat treatment to the rough model increases adhesion force because of the expanded contact area. The contact area is speculated to be more influential to the adhesion force rather than the internal stress of the CNT on the rough Ag thin film, because the CNT on the rough model contains internal stress regardless of the heat treatment. Therefore, as demonstrated by simulation results, the heat treatment can prevent delamination or wear of CNT coating on a rough metallic substrate by thermal wetting phenomena.

• Advances in nano research
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• v.12 no.3
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• pp.253-261
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• 2022

Numerical modelling of an integrated Carbon NanoTube (CNT) membrane is only achievable if probable deformations and realistic alterations from a perfect CNT membrane are taken into account. Considering the possible forms of CNTs, bending is one of the most probable deformations in these high aspect ratio nanostructures. Hence, investigation of effect associated with bent CNTs are of great interest. In the present study, molecular dynamics simulation is utilized to investigate fluid flow dynamics in deformed CNT membranes, specifically when the tube cross section is not affected. Bending in armchair (5,5) CNT was simulated using Tersoff potential, prior to flow rate investigation. Also, to study effect of inclined entry of the CNT to the membrane wall, argon flow through generated inclined CNT membranes is examined. The results show significant variation in both cases, which can be interpreted as counter-intuitive, since the cross section of the CNT was not deformed in either case. The distribution of fluid-fluid and fluid-wall interaction potential is investigated to explain the anomalous behavior of the flow rate versus bending angle.