http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Reversibly bonded nanocapillaries by electrostatic forces for directed alignment of carbon nanotubes
Pilnam Kim(김필남),Kahp Y. Suh(서갑양) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.11
Reversibly bonded nanocapillaries (500 ? 50 ㎚) were fabricated on gold and silicon substrates using electrostatic forces that can be generated on a rigiflex mold upon removal from an original, engraved silicon master. Polyethylene glycol diacrylate (PEG-DA) was used as a rigiflex mold material with highly negative surface charges (zeta potential: - 113.55 ㎽).). The rigiflex, transparent PEG-DA mold spontaneously wets gold or silicon substrate via electrostatic attraction, forming reversibly bonded nanocapillaries without any surface modifications or external stimuli. Using these nanocapillaries, nanolines or nanowells were fabricated without residual layer along with one-dimensional arrays of single-walled carbon nanotubes (SWCNTs) and gold nanoparticles(NPs).
UV 나노임프린팅을 이용한 단일(單一) 나노 브리지 구조의 제작
곽노균(Rhokyun Kwak),정훈의(Hoon Eui Jeong),서갑양(kahp Y. Suh) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5
In this paper, a simple vacuum-assisted UV nanoimprint lithography (NIL) method is presented for fabricating well-defined monolithic nanobridges. A droplet of UV-curable resin of polyurethane acrylate (PUA) is dispensed and imprinted to form microscale structures with PDMS mold and subsequent curing for several seconds. Under proper conditions, the top layer is partially cured by the trapped air and provides further nanofabrication upon application of a nanoscale PUA mold at vacuum. It is noted that a pressure gradient is generated between a contacting and a non-contacting parts with the mold, resulting in a flow of the partial cured pre-polymer into the void regions. Finally, monolithic nanobridges is fabricated with high aspect ratio in large area. These nanobridges are potentially useful for smart optical and electronic devices.
Poly(ethylene glycol)을 생체적합 및 흡착 방지 마이크로/나노채널 제작 및 특성 연구
김필남(Pilnam Kim),정훈의(Hoon Eui Jeong),서갑양(Kahp Y. Suh) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6
We present a simple solvent-assisted capillary molding method to fabricate zinc oxide (ZnO) nanostructures using an ultraviolet (UV) curable polyurethane acrylate (PUA) mold. A thin film of the ZnO sol-gel precursor solution in methyl alcohol was prepared by spin coating on a solid substrate and subsequently a nanopatterned PUA mold was brought in conformal contact with the substrate under a slight physical pressure (~ 3.5 bar). After annealing at 230 °C for 4 hrs, well-defined ZnO nanostructures formed with feature size down to ~ 50 ㎚ aided by capillary rise and solvent evaporation. It was found that the height of capillary rise highly depended on the applied pressure. A simple experimental setup was devised to examine the effects of pressure, revealing that the optimum pressure ranged from 3.5 to 5 bars. Also, ZnO nanorods could be selectively grown on the patterned regions using the seed layer as a pseudocatalyst when the width of seed layer was larger than ~ 200 ㎚.
Two-step capillary force lithography for fabricating biomimetic, superhydrophobic surfaces
Hoon Eui Jeong(정훈의),Rhokyun Kwak(곽노균),Jae Kwan Kim(김재관),Kahp Y. Suh(서갑양) 대한기계학회 2008 대한기계학회 춘추학술대회 Vol.2008 No.5
Inhibition effects in UV radiation curing by oxygen were utilized for fabricating monolithic, micro/nanoscale hierarchical polymer structures via two-step UV-assisted capillary force lithography. It was found that the UV exposure time for the partial curing of microstructure was a crucial parameter; a shorter exposure time induced collapse of the underlying microstructure while a longer time gave rise to non-fluidity of the microstructure. The partial curing is attributed to inhibition of UV cross linking by trapped or permeated oxygen within mold cavities. Using this method, various dual-scale hierarchical structures were fabricated with minimum resolution to 50 nm over a large area (5×5 ㎠) in a fast and reproducible manner.
Capillary-driven Rigiflex Lithography for Fabricating High Aspect-Ratio Polymer Nanostructures
정훈의(Hoon Eui Jeong),이성훈(Sung Hoon Lee),김필남(Pilnam Kim),서갑양(Kahp Y. Suh) 한국가시화정보학회 2007 한국가시화정보학회지 Vol.5 No.1
We present simple methods for fabricating high aspect-ratio polymer nanostructures on a solid substrate by rigiflex lithography with tailored capillarity and adhesive force. In the first method, a thin, thermoplastic polymer film was prepared by spin coating on a substrate and the temperature was raised above the polymer’s glass transition temperature (T<SUB>g</SUB>) while in conformal contact with a poly(urethane acrylate) (PUA) mold having nano-cavities. Consequently, capillarity forces the polymer film to rise into the void space of the mold, resulting in nanostructures with an aspect ratio of ~ 4. In the second method, very high aspect-ratio (>20) nanohairs were fabricated by elongating the pre-formed nanostructures upon removal of the mold with the aid of tailored capillarity and adhesive force at the mold/polymer interface. Finally, these two methods were further used to fabricate micro/nano hierarchical structures by sequential application of the molding process for mimicking nature’s functional surfaces such as a lotus leaf and gecko foot hairs.
배원규(Won Gyu Bae),최재훈(Jae Hoon Choi),서갑양(Kahp Y. Suh) 한국생산제조학회 2011 한국생산제조시스템학회 학술발표대회 논문집 Vol.2011 No.4
나노 스케일의 구조물은 반도체, 바이오 등의 여러 가지 연구 분야에서 폭넓게 사용되고 있다. 하지만 나노 구조물의 제작은 여전히 복잡한 공정을 필요로 하고 비용 또한 많이 든다. 따라서 본 연구에서는 형상 기억 폴리머를 나노 임프린트 리소그래피몰드로 이용하여 스케일 다운 과정을 통해 나노 구조물 제작 방법을 제안하였다. 형상 기억 폴리머는 열에 의해 원래의 기억된 형상으로 돌아가는 성질이 있는데 이러한 성질을 이용하여 제작이 쉬운 마이크로 구조물로부터 나노 구조물을 제작하고자 하는 것이다. 이 방법은 하나의 몰드로부터 여러 가지 사이즈의 나노 구조물을 제작할 수 있다는 장점을 가지고 있으며 간단한 제작방법과 경제적이라는 것이 가장 큰 특징이다.
정훈의(Hoon Eui Jeong),이성훈(Sung Hoon Lee),김필남(Pilnam Kim),서갑양(Kahp Y. Suh) 대한기계학회 2006 대한기계학회 춘추학술대회 Vol.2006 No.6
A new, innovative approach for fabricating high aspect-ratio polymer nanohairs is presented, which is based on an elongation of polymer nanostructures by interfacial energy modulation. Calculation of two interfacial energies at the mold/polymer and the polymer/substrate interface indicates that the two energies should be compatible for successful elongation of the polymer nanostructures. By this approach, high aspectratio polymer (PMMA and PS) nanostructures were fabricated with maximum ratio up to ~ 25 on a solid substrate with good uniformity and reproducibility. A double-sided flexible tape fabricated by this approach shows good adhesive property and super-hydrophobicity, demonstrating the unique fabrication ability and applicability of this method.