• Journal of the Korean Vacuum Society
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• v.11 no.1
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• pp.59-67
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• 2002

The structures and properties of Cu nanowires have been investigated using molecular dynamics simulations. Cylindrical multi-shell Cu nanowires maintain their structures at room temperature and their structural properties are different from the structural properties of nanowires with face-centered-cubic structure. The results from nanopillar and tensile testing of cylindrical multi-shell Cu nanowire showed structures related to pentagonal needle-like crystal structures. Since the subunits of pentagonal nanowire with needle-like crystal are face-centered-cubic structure, pentagonal multi-shell nanowires are stable one-dimensional structures in nanostructured materials.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.92.1-92.1
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• 2018

표면증강 라만 산란(Surface Enhancement Raman Scattering, SERS) 기판의 경우, 규칙적인 배열을 갖는 나노구조 및 나노패턴 기판과 금속 나노구조의 고밀도 패킹이 고감도 화학물질 검출에 중요하다. 또한 폭넓은 응용 가능성에도 불구하고 기판 제작의 비용이 높고 재현성이 떨어져 상용화에 어려움을 겪고 있다. 본 연구에서는 다공성 알루미나(Anodic Aluminum Oxide, AAO)를 사용하여 Ag 나노입자가 코팅된 나노기둥 배열(Nanopillar array)을 갖는 고분자 필름의 SERS-active 기판을 제작하여 공정비용을 낮추고, 대면적화로 생산성을 높이고자 한다. 다단계 양극산화 공정과 복제 기술을 통해 다양한 지름과 높이를 갖는 맥주병 형상의 나노기둥 배열을 제조하였고, aspect ratio가 2.3인 나노기둥 배열에서 최대의 SERS 신호 강도와 높은 재현성을 확인하였다. SERS 신호의 세기는 Ag 나노입자가 코팅된 나노기둥 배열의 열처리 온도와 분석 물질의 농도에 따라 비례하며 이를 바탕으로 정량적인 고감도 진단, 바이오 화학 물질 센서에 매우 적합함을 알 수 있다.

• Applied Microscopy
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• v.50
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• pp.26.1-26.3
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• 2020

The biocompatible polyurethane acrylate (PUA) nanopillars were fabricated by soft lithography using three different sizes of nanobeads (350, 500, and 1000 nm), and the human adipose-derived stem cells (hASCs) were cultured on the nanopillars. The hASCs and their various behaviors, such as cytoplasmic projections, migration, and morphology, were observed by high resolution images using a scanning electron microscope (SEM). With the accurate analysis by SEM for the controlled sizes of nanopillars, the deflections are observed at pillars fabricated with 350- and 500- nm nanobeads. These high-resolution images could offer crucial information to elucidate the complicated correlations between nanopillars and the cells, such as morphology and cytoplasmic projections.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.296-296
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• 2013

Supercapacitor is a capacitor with extraordinarily high energy density, which basically consists of current collector, active material and electrolyte. Ruthenium oxide ($RuO_2$) is one of the most widely studied active materials due to its high specific capacitance and good electrical conductivity. In general, it is known that the coating of $RuO_2$ on nanoarchitectured current collector shows improved performance of energy storage device compared to the coating on the planar current collector. Especially, the surface structure with standing coaxial nanopillars are most desirable since it can provide direct paths for efficient charge transport along the axial paths of each nanopillars and the inter-nanopillar spacing allows easy access of electrolyte ions. However, well-known fabrication methods for metal or metal oxide nanopillars, such as the process using anodize aluminum oxide (AAO) templates, often require long and complicated nanoprocess.In this work, we developed relatively simple method fabricating indium tin oxide (ITO) nanopillars via sputtering. We also electrodeposited $RuO_2$ nanoparticles onto these ITO nanopillars and investigated its physical and electrochemical properties.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.539-544
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• 2020

A three-dimensional (3D) porous polyaniline (PANI) film was fabricated by a combined photo-and soft-lithography technique based on a large-area nanopillar array, followed by a controlled chemical dilute polymerization. The as-obtained 3D PANI film consisted of hierarchically interconnected PANI nanofibers, resulting in a 3D hierarchical nanoweb film with a large surface and open porous structure. Using electrochemical measurements, the resulting 3D PANI film was demonstrated as a flexible pH sensor electrode, exhibiting a high sensitivity of 60.3 mV/pH, which is close to the ideal Nernstian behavior. In addition, the 3D PANI electrode showed a fast response time of 10 s, good repeatability, and good selectivity. When the 3D PANI electrode was measured under a mechanically bent state, the electrode exhibited a high sensitivity of 60.4 mV/pH, demonstrating flexible pH sensor performance.