• 대한기계학회논문집B
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• 제37권12호
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• pp.1159-1165
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• 2013

파우더 블라스팅은 미세 유리가공법으로서 가공속도가 빠르고 저비용의 장점이 있지만 유리를 취성파괴 시키기 때문에 표면거칠기가 좋지않다. 블라스팅된 표면에 저압의 워터젯을 분사하여 표면에서의 연마 슬러리의 흐름을 통해 표면거칠기를 저감할 수 있다. 본 연구에서는 소다라임 유리에 블라스팅으로 마이크로 채널을 가공한 후 워터젯을 연속 적용하고, 마이크로 채널의 표면거칠기 및 단면 형상의 변화의 과정을 관찰하였다. 워터젯의 적용결과, 초기단계에서는 블라스팅에 의한 미세 요철이 제거되었고, 이후 표면하부의 크랙이 제거되어 평균 표면거칠기 50 nm 근방의 매끈한 표면을 얻을 수 있었다. 표면거칠기 저감에 동반하여 채널단면의 확장 과정도 함께 관측하였다. 마지막으로 제안한 방법에 의해 미세유체칩의 가공 결과를 제시하였다.

• 소성∙가공
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• 제15권9호
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• pp.692-696
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• 2006

Micro fabrication of polymeric materials becomes increasingly important. And it is considered as a low-cost alternative to the silicon or glass-based Micro Electro-Mechanical System(MEMS) technologies. In the present study, micro channels were fabricated via LiGA(Lithographie, Galvanoformung, Abformung) process used for Capillary Electrophoresis(CE) chip. Taguchi method was applied to investigate the effects of process conditions in injection molding(melt temperature, injection speed, mold temperature and packing pressure) on the transcription characteristics of the micro channel. It was found that the skin layer disturbs a formation of micro channel. Furthermore, mold temperature and injection speed were two important factors to affect the replication characteristics of micro channel.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.671-674
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• 2008

We investigate the slippage effect in a micro-channel depending on the surface characteristics; hydrophilic, hydrophobic, and super-hydrophobic wettabilities. The micro-scale grooves are fabricated on the vertical wall to make the super-hydrophobic surfaces, which enable us visualize the flow fields near walls and directly measure the slip length. Velocity profiles are measured using micro-particle image velocimetry (Micro-PIV) and compared those in the hydrophilic glass, hydrophobic PDMS, and super-hydrophobic PDMS micro-channels. To directly measure the velocity in the super-hydrophobic micro-channel, the transverse groove structures are fabricated on the vertical wall in the micro-channel. The velocity profile near the wall shows larger slip length and, if the groove structure is high and wide, the liquid meniscus forms curves into the valley so that the wavy flow is created after the grooves.

• 유체기계공업학회:학술대회논문집
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• 유체기계공업학회 2004년도 유체기계 연구개발 발표회 논문집
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• pp.754-760
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• 2004

The miniaturization and integration are trend of modern blood analyses. Micro-Bio-Fluidics plays an important role in a micro blood analysis system. In this paper, analysis and design technology for blood analysis system is presented. Numerical simulations of a blood flow in micro separator and reservoir are conducted. As a result, we suggest on-chip micro separator, which performed plasma separation from whole blood in micro channels.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.1093-1097
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• 1995

A micro ion drag pump with planar electrodes on a glass substrate is fabricated and tested. the pump consisted of a 2- dimensional electrode pair array is driven by DC voltage using unipolar conduction. Ethy alcohol is pumped in both directions, and the flow rate and the pressure are measured, in channels of depth 100 .mu m or 200 .mu. m and width fixed at 3mm. It is found that the pump could be fabricated easily and at lower cost than the micro ion drag pumps previously investigated.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.173-174
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• 2007

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.274-279
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• 2002

In this paper, the development process of an unique and creative micro/nano-structure fabrication technique based on micro/nano-tribology are reviewed and discussed. The so-called Mechano-Chemical Process(MCP), which has been developed since 1995 by Tribology Research Laboratory at Yonsei University with the motivation to overcome the demerits of the conventional photolithographic techniques, is based on the fundamental understanding of the interaction between the tool tip and the workpiece surface. This process is a maskless process which offers tremendous flexibility in surface patterns that can be created on a workpiece surface without using any capital intensive equipment. It Is capable of fabricating the prototypes of micro/nano-components, micro- structured surface with various geometries, micro-molds for making polymer or metal parts, and micro-fluidic channels for lab-on-a- chip

• 한국공작기계학회논문집
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• 제16권6호
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• pp.168-174
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• 2007

A ceramic glass mold was developed for micro hot-embossing and replicated polymer parts are fabricated. The glass-ceramic micro mold could be fabricated with a laser process and a wet etching process and the fabrication time could be saved a lot. Various polymer micro structures can be obtained by hot-embossing. The process parameters such as ho-embossing temperatures or pressures were investigated and optimized. This process can be applied for fabrication of micro structures for flip-chips or micro fluidic channels for bio-engineering. The advantages and disadvantages of this process are discussed, too.

• 한국정밀공학회지
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• 제31권5호
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• pp.389-394
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• 2014

In this paper, we report a new manufacturing method for friction reduction using micro-AAJ (abrasive air-jet) machining. AAJ machining employs compressed air to accelerate a jet of high-speed particles to mechanically machine features, including micro-channels and micro-holes, into glass, metal, or polymer substrates for use in microfluidics, MEMS (micro electromechanical systems). And we introduce the micro-AAJ machining system, which consists of a micro-AAJ nozzle and a five-axis positioning system. Various micro-AAJ nozzles can be used, depending on the required surface structure, and three-dimensional machining is possible. We machined samples under six different conditions and describe machining results obtained while using it. We also measured the coefficient of friction of micro-textured surfaces. We report the coefficient of friction of micro-textured surfaces patterned using micro-AAJ machining for engine piston ring.

• 한국통신학회논문지
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• 제21권6호
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• pp.1398-1415
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• 1996

Instead of using three charge-coupled devices (CCDs) for the corresponding color channels, most consumer's most consummer's color macmorders reconstruct color images by using only one CCD with a color filter array (CFA), which periodically samples different color signals. By this reson the resulting image cannot produce the full resolution of the input image. More sepecifically, a single-CCD color camcorder reconstructs red, greed, and blue color channels from a color filter array followed by a CCD. During the reconstruction process, color cross-talk among channels (interchannel distortion) and eriodically space-verying blur (intrachannel distortion) occur. The proposed restoration system reduces distortions due to interchannel interference, and then restores each color channel by removing the corresponding intrachannel distortion. Experimental results show that the proposedsystem provides the improved image in oth objective and subjective senses. A major advantage of the proposed system is feasible to real-time image improvement because it can be implemented by a finite impulse response (FIR) filter structure.