• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제44회 동계 정기학술대회 초록집
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• pp.274-274
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• 2013

We fabricate encapsulation-layer of OLED panel from organic-inorganic hybrid thin film by atomic layer deposition (ALD) molecular layer deposition (MLD) using Al2O3 as ALD process and Adipoyl Chloride (AC) and 1,4-Butanediamine as MLD process. Ellipsometry was employed to verify self-limiting reaction of MLD. Linear relationship between number of cycle and thickness was obtained. By such investigation, we found that desirable organic thin film fabrication is possible by MLD surface reaction in monolayer scale. Purging was carried out after dosing of each precursor to eliminate physically adsorbed precursor with surface. We also confirmed roughness of the organic thin film by atomic force microscopy (AFM). We deposit AC and 1,4-Butanediamine at $70^{\circ}C$ and investigated surface roughness as a function of increasing thickness of organic thin film. We confirmed precursor's functional group by IR spectrum. We calculated WVTR of organic-inorganic hybrid super-lattice epitaxial layer using Ca test. WVTR indicates super-lattice film can be possibly use as encapsulation in flexible devices.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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• pp.418-418
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• 2012

We fabricated a new type of hybrid film using molecular layer deposition (MLD). The MLD is a gas phase process analogous to atomic layer deposition (ALD) and also relies on a saturated surface reaction sequentially which results in the formation of a monolayer in each sequence. In the MLD process, polydiacetylene (PDA) layers were grown by repeated sequential surface reactions of titanium tetrachloride and 2,4-hexadiyne-1,6-diol with ultraviolet (UV) polymerization under a substrate temperature of $100^{\circ}C$. Ellipsometry analysis showed a self-limiting surface reaction process and linear growth of the hybrid films. Polymerization of the hybrid films was confirmed by infrared (IR) spectroscopy and UV-Vis spectroscopy. Composition of the films was confirmed by IR spectroscopy and X-ray photoelectron (XP) spectroscopy. The titanium oxide cross-linked polydiacetylene (TiOPDA) hybrid films exhibited good thermal and mechanical stabilities.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1865-1868
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• 2003

This paper provides a new method for hybrid machining, particularly suited to micro fabrication applications such as micro point, micro line, micro structure, micro partition and so on. Developed micro fabrication process by electrical discharge machining (EDM) and electrical discharge deposition (EDD) with metal powder (Ti, Fe) has been studied to build TiC or FeC structure. Titanium powder or iron powder is supplied from working fluid (kerosene or de-ionized water with powder) and adheres on a workpiece by the heat and electric power caused by the electrical discharge. The use of a tool electrode is expected to keep powder concentration high in the gap between a workpiece and a tool electrode and to accrete powder material on the workpiece. The deposition is tried under various electrical conditions (workpiece. tool electrode, working fluid, discharge current, voltage and powder etc.). On the other hand. using electrical discharge machining (EDM) with the same tool electrode, it can be used as a removal process (cutting) by electro erosion at the same time. Therefore. this new method can do a hybrid machining to build up and down a structure with the workpiece.

• 한국기계가공학회지
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• 제17권1호
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• pp.108-115
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• 2018

In bone tissue engineering, polycaprolactone (PCL) is one of the most widely used biomaterials to manufacture scaffolds as a synthetic polymer with biodegradability and biocompatibility. The polymer deposition system (PDS) with four axis heads, which can dispense bio-polymers, has been used in scaffold fabrication for tissue engineering applications. A dual-head deposition technology of PDS is an effective technique to fabricate 3D scaffolds. The electrospinning technology has been widely used to fabricate porous and highly interconnected polymer fibers. Thus, PDS can fabricate nanofiber-combined hybrid scaffolds using fused deposition modeling (FDM) and electrospinning methods. This study aims to fabricate nanofiber-combined scaffolds with uniform nanofibers using PDS. The PCL nanofibers were fabricated and evaluated according to the fabrication process parameters. PCL nanofibers were successfully fabricated when the applied voltage, tip-to-collector distance, flow rate, and solution concentration were 5 kV, 1 cm, 0.1 ml/h, and 8 wt%, respectively. The cell proliferation was evaluated according to the electrospinning time. Scanning electron microscopy was used to acquire images of the cross-sectioned hybrid scaffolds. The cell proliferation test of the PCL and nanofiber-combined hybrid scaffolds was performed using a CCK-8 assay according to the electrospinning time. The result of in-vitro cell proliferation using osteosarcoma MG-63 cells shows that the hybrid scaffold has good potential for bone regeneration.

• 접착 및 계면
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• 제21권4호
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• pp.143-155
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• 2020

Sol-Gel 공정을 통해서 제조되는 유-무기 하이브리드 화합물들은 방청 코팅, 방빙 코팅(Anticing), 자가 세정 코팅, 반사 방지 코팅 등과 같은 기능성 코팅 재료로 널리 사용되어져 왔다. 특히 소수성 코팅 표면을 제조하기 위해서는 코팅표면의 표면에너지가 낮고 코팅 표면의 조도를 제어가 요구된다. 표면에너지와 표면 조도를 조절하는 전형적인 공정은 in-situ fabrication 공정, 'Pre-fluorinating/Post-roughening', 'Pre-roughening/ Post-fluorinating이다. 본 연구에서는 in-situ fabrication 공정인 Particle-Binder 공정을 이용해서 소수성 코팅표면을 제조하였다. 3관능기 유기실란화합물과 불소 함유 유기실란 화합물과의 가수분해 및 축합반응을 통해 제조된 불소함유 유-무기 하이브리드를 바인더로 사용하여서 무기물 나노입자와 혼합하여 소수성 코팅액을 제조하고 유리 기재 위에 스핀코팅 후 열건조하여서 코팅막을 제조하였다. 바인더인 유-무기 하이브리드 화합물의 불소 함유 실란화합물의 첨가량, 첨가순서, 무기물 나노입자 첨가량에 따른 코팅막의 물성 변화를 조사하였다. 분석결과 불소 함량이 10 wt%인 유-무기 하이브리드 화합물(GPTi-HF10)을 바인더로 사용하여서 제조된 코팅막이 가장 소수성이 우수하였으며 수접촉각은 (107.52 ± 1.6°), 이 바인더와 무기물 나노입자의 무게비가 1:3인 경우(GPTi-HF10-MS 3.0)에 가장 높은 수접촉각(130.84±1.99°)을 나타내었다.

• 한국기계가공학회지
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• 제12권6호
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• pp.17-22
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• 2013

Recently, microcellular polymer films have been widely used as absorbents, support cells, and sensors in the industrial fields of IT, NT, BT, and ST. The conventional fabrication methods of microcellular polymer films are not only more complicated than those of non-microcellular polymer films, but also require a longer production time. In this paper, we propose a new hybrid fabrication method for microcellular polymer films; films can be rapidly made using UV laser processing with chemical blowing agents. The experimental results show that the number of the micropores increased with respect to the laser fluence and the concentration of the chemical blowing agents.

• 한국기계가공학회지
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• 제18권11호
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• pp.103-108
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• 2019

The cooling rate and the uniformity of mold temperature, in the injection molding process, possess great influences on the productivity and quality of replications. The conformal cooling channel, which is of a uniform spacing from the mold cavity by the metal additive manufacturing process, receives much attention recently. The purpose of this study is to develop a mold core with a curved conformal cooling channel for a pottery-shaped thick-wall cosmetic container through the hybrid method of direct metal tooling (DMT) process. In this study, we design a mold core that contains the curved cooling channel for the container. A method that divides the cavity is proposed and the DMT process is carried out to form the curved cooling channel. The test mold core, with the curved conformal cooling channel, has been fabricated by the proposed method to confirm the feasibility of the design concept. We show that no leakage is observed for the additive manufactured test mold core, and its physical properties demonstrate that it can be sufficiently used as the injection mold core.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.286-289
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• 2003

We investigated the influence of the properties of substrate material on the separation efficiency in microchip electrophoresis. We fabricated the various microchips and studied separation efficiency in microchannels composed of a single material such as quartz, glass, polydimethylsiloxane (PDMS), and polymethylmetha crylate (PMMA), as well as hybrid micro channels composed of different materials. New fabrication process for glass chip was suggested and some treatment is added to improve fabrication process in other chip. Separation efficiency was compared by measuring migration times and bandwidths of EOF and analytes in each microchip. The efficiency is the function of migration time, which is affected by the electroosmotic flow (EOF), and bandwidth of an analyte. EOF is highly dependent upon the characteristics of a microchannel wall surface. Migration time was more reproducible in silica chips than that of PDMS chip and more band broadening was observed in the microchip composed of hybrid material due to non-uniformity of surface charge density at the walls of the channel.

• 소성∙가공
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• 제19권6호
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• pp.352-356
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• 2010

This paper was designed to fabricate the micro-spur gear by the LIGA and hybrid powder extrusion process. It is important to manufacture a micro-die with a high aspect ratio and determine appropriate extrusion conditions for a microforming. Ni has been used to fabricate micro-dies. LIGA process was capable to produce micro-extrusion dies with close tolerance, longer bearing length and adequate surface quality. Superplastic Al-78Zn powders have the great advantage in achieving deformation under low stresses and exhibiting good micro-formability with average strain rate raging from $10^{-3}$ to $10^{-2} s^{-1}$ and constant temperature ranging from 503 to 563K. Al-78Zn powders were compacted into a cylindrical shape ($\Phi3\times$h10mm) under compressive force of 10kN and, subsequently, the compacted powders were extruded by the hybrid powder extrusion process controlling of the temperature holing time for a improvement on formability of Al-22Zn powder. Micro-extrusion has succeeded in forming micro-gear shafts.

• 한국해양공학회지
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• 제19권1호
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• pp.57-63
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• 2005

The objective of this research is to investigate the mechanical characteristics of the hybrid fiber reinforced composite rebar, which is manufactured from a braidtrusion process. Braidtrusion is a direct composite fabrication technique, utilizing in-line brading and the pultrusion process. hz order to obtain the mechanical behavior of the glass fiber, carbon fiber, and kevlar fiber, the tensile tests are carried out. The results of the fibers are compared with that of steel. Hybrid rebar specimens with various diameters, ranging from model size (3 mm) to full-scale size (9.5 mm), and various cross sections, such as solid and hollow shape, have been manufactured from the braidtrusion process. The tensile and bending tests for the case of the hybrid rebar, the conventional GFRP rebar, and the steel bar have been carried out. The results of the experiments show that the hybrid rebar is superior to the conventional GFRP rebar and the steel bar, from the viewpoint of tensile and bending characteristics.