• 한국반도체및디스플레이장비학회:학술대회논문집
• /
• 한국반도체및디스플레이장비학회 2006년도 춘계학술대회
• /
• pp.105-108
• /
• 2006

We investigated the fluidic gas-driven carbon-nanotube motor based on multi-wall carbon nanotubes and fluidic gas flow. Since the origination of the torque was the friction between the carbon nanotube surface and the fluidic gases, the density and the flow rate of the working gas or liquid were very important for the carbon nanotube motor. Molecular simulation results showed that multi-wall carbon nanotubes with very low rotating energy barriers could be effectively used for fluidic gas-driven carbon-nanotube motors.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2006년도 춘계학술대회 논문집
• /
• pp.465-466
• /
• 2006

A single-wall carbon nanotube (SWCNT) has been studied as a material of Nano-Eletro-Mechanical-System (NEMS) device together with various nanowires. In order for oscillation of a multi-wall carbon nanotube (MWCNT) or a single-walled carbon nanotube (SWCNT) on plane surface, it needs suspension of a CNT across trench electrodes. So we propose fabrication method of a MWCNT resonator using dielectrophoresis and show successful results of suspeneded MWNT. Thin electrodes with large gaps could not suspend small diameter MWNT but thicker electrodes could. Thin MWNT could be suspended only when the electrode gap was reduced.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 춘계학술대회
• /
• pp.542-546
• /
• 2004

Fully non-local Quasicontinuum method using sub-divided region with Hermite interpolation function is proposed for simulation of carbon nanotube. Tersoff-Brenner potential is adopted for interaction of bonded atoms and also van der Waals force for non-bonded interaction. Bending of single wall carbon nanotube with chirality (20,0) and 15nm length is simulated up to 90 degree. Bending of double wall carbon nanotube with chirality (20,0) and (12,0) is simulated up to 65 degree. Bending of four wall carbon nanotube is simulated up to 45 degree.

• 한국정밀공학회지
• /
• 제21권6호
• /
• pp.167-171
• /
• 2004

In this paper, we proposed a new method to control the length of carbon nanotube using electrochemical etching. We made a nano probe that was composed of the tungsten tip and multi-wall carbon nanotube. The nano probe was placed on the nano stage and the carbon nanotube on the nano probe was etched in the electrolyte solution with the applied voltage. The overall procedures were done under optical microscope and can be monitored. We can obtain a nano probe with proper length through this procedure.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2002년도 International Meeting on Information Display
• /
• pp.689-691
• /
• 2002

Well-aligned multi-wall carbon nanotubes (MWCNTs) have been grown on both Coming glass and silicon substrates at about 400 $^{\circ}C$ by a modified plasma - enhanced chemical vapor deposition system. We have investigated laser irradiation effect on carbon nanotube surface by using an ultra - violet laser. The laser operated to modify structural defect of was carbon nanotube and to ablate possible contamination of carbon nanotube surface. The morphology and surface transformation of MWCNTs as analyzed by a SEM. In addition, the field emission measurement was also carried out in a vacuum chamber with a $10^{-7}$ Torr base pressure by applying bias voltages up to 1000V.

• 한국전기전자재료학회논문지
• /
• 제17권8호
• /
• pp.812-822
• /
• 2004

This paper shows that carbon nanotubes can be applied to a nanopipette. Nano space in atomic force microscope multi-wall carbon nanotube tips is filled with molecules and atoms with charges and then, the tips can be applied to nanopipette when the encapsulated media flow off under applying electrostatic forces. Since the nano space inside the tips can be refilled, the tips can be permanently used in ideal conditions of no chemical reaction and no mechanical deformation. Molecular dynamics simulations for nanopipette applications demonstrated the possibility of nano-lithography or single-metallofullerene-transistor array fabrication.

• 접착 및 계면
• /
• 제11권4호
• /
• pp.174-180
• /
• 2010

다중벽탄소나노튜브를 표면처리하여 polymethylmethacrylate (PMMA) 기재에 첨가하여 제조한 고분자 복합재료에서 탄소나노튜브의 표면처리가 계면 및 열전도도에 미치는 효과를 고찰하였다. Coagulation 방법과 atomic transfer radical polymerization (ATRP) 방법을 사용하여 탄소나노튜브를 표면 처리 하여 사용하였으며, ATRP 방법을 적용하여 제조한 복합재료는 coagulation 방법을 사용하여 제조한 복합재료보다 높은 열전도도와 투과도를 가졌다. 순수 PMMA의 열전도도가 0.21 W/mK인데 비하여 ATRP 방법으로 처리한 1 wt%의 탄소나노튜브를 첨가하였을 경우 0.38 W/mK로 열전도도가 향상되었다. 탄소나노튜브와 PMMA기재의 계면을 주사전자현미경을 이용하여 관찰한 결과 탄소나노튜브의 표면처리에 의해 기재 내에 분산이 향상되고 고분자기재-탄소나노튜브 계면에서의 접촉이 용이해져 포논산란이 감소되어 광 투과성을 가지면서 열전도도가 향상된 것으로 보인다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2023년도 봄 학술논문 발표대회
• /
• pp.185-186
• /
• 2023

Recently, a lot of nano-scale material technology development and research have been conducted in construction fields to improve the compressive strength and durability of cement-based Composites. There are some studies that have confirmed the properties and application effects of cement-based complex using each nanomaterial, but development and research using both materials are relatively limited. This study sought to confirm the effect of multi-wall carbon nanotubes (MWCNT) and nanosilica, which are representative construction nanomaterials, on the compressive strength, voids, and microstructure formation of cement. The purpose was to produce a cement composite by changing the mixing rate of the two nanomaterials, and to find the optimal mixing amount considering its mechanical and rheological properties.

• Smart Structures and Systems
• /
• 제18권2호
• /
• pp.217-231
• /
• 2016

The present work aims to develop piezoresistive sensors of excellent piezoresistive response attributable to change in nanoscale structures of multi-wall carbon nanotube (MWNT) embedded in cement. MWNT was distributed in a cement matrix by means of polymer wrapping method in tandem with the ultrasonication process. DC conductivity of the prepared samples exhibited the electrical percolation behavior and therefore the dispersion method adopted in this study was deemed effective. The integrity of piezoresistive response of the sensors was assessed in terms of stability, the maximum electrical resistance change rate, and sensitivity. A composite sensor with MWNT 0.2 wt.% showed the lowest stability and sensitivity, while the maximum electrical resistance change rate exhibited by this sample was the highest (96 %) among others and even higher than those found in the literature. This observation was presumably attributed by the percolation threshold and the tunneling effect. As a result of the MWNT content (0.2 wt.%) of the sensor being near the percolation threshold (0.25 wt.%), MWNTs were close to each other to trigger tunneling in response of external loading. The sensor with MWNT 0.2 wt.% was able to maintain the repeatable sensing capability while sustaining a vehicular loading on road, demonstrating the feasibility in traffic flow sensing application.

• 한국정밀공학회지
• /
• 제24권3호
• /
• pp.134-139
• /
• 2007

We report the suspension of individual multi-walled carbon nanotubes (MWNTs) from the bottom substrate using deep trench electrodes that were fabricated using optical lithography. During drying of the solution in dielectrophoretic assembly, the capillary force pulls the MWNT toward the bottom substrate, and it then remains as a deformed structure adhering to the bottom substrate after the solution has dried out. Small-diameter MWNTs cannot be suspended using thin electrodes with large gaps, but large-diameter MWNTs can be suspended using thicker electrodes. We present the statistical experimental results for successful suspension, as well as the feasible conditions for a MWNT suspension based on a theoretical approach.