• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1540-1545
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• 2004

Measurement of concentration fields in a micro-channel is the crucial technology in the area of Lab-on-a-chip to be used for various bio-chemical applications. It is wel-known that the only possible way to measure the concentration field in the micro-channel is using micro-LIF(Laser Induced Fluorescence) method. However, an accurate concentration field at a given cross plane in a micro-channel has not been made so far due to the limit of light illumination. The present study demonstrates a novel method to provide an ultra thin laser sheet beam having 5 microns thickness by a micro focus laser line generator. Nile Blue A was used as fluorescent dye for LIF measurement. The laser sheet beam illuminates an exact plane of concentration measurement in the micro-channel to increase the signal to noise ratio and reduce the depth uncertainty considerably.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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• pp.304-309
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• 2004

As it is difficult to construct a micro-fluidic system composed of micro-mixers, micro-channels and/or micro-chambers in a single process, an assembly process is typically used. The assembling and bonding of micro-parts, however, introduces other problems. In this work, a virtual assembly process was developed that can be used to design various micro-fluidic systems before actual fabrication commences. In the process, the information required for the micro-stereolithography process is generated automatically. Consequently, complex micro-fluidic systems can be fabricated in a single process, thereby avoiding the need for additional assembly or bonding processes. Using the developed process, several examples were fabricated.

• 한국가시화정보학회지
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• 제5권1호
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• pp.43-48
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• 2007

Micro-PIV(particle image velocimetry) has been widely used to measure the velocity of micro flow. Although this micro-PIV method can give accurate 2D instantaneous velocity information of mea-surement plane, it cannot resolve the out of plane component of velocity vectors. Lots of the micro fluidic devices generate three-dimensional flow and 3D measurement of velocity is useful to understand the physics of micro flow phenomena. In this study, we constructed stereoscopic micro-PIV(SMPIV) system and applied this method to the impinging micro jet flow. The results show that this method can produce accu-rate 3D reconstruction of micro jet flow.

• 소성∙가공
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• 제15권9호
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• pp.654-659
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• 2006

In this paper, the real shapes of micro tool deflection were observed. In micro endmilling process, micro tool deflection generates very serious problems in contrast to macro tool deflection. For analyzing the micro tool deflection, the trend of micro tool deflection was observed using real captured images in this paper. To get the real images of micro tool deflection, micro slot cutting processes were executed under cutting volume using micro endmill($Dia.\;200{\mu}m$) and real images of tool deflection were obtained during cutting processing by high-speed camera. Finally, the extent of tool deflection was calculated by the deflection angle according to cutting volume.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.858-861
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• 2001

As the application fields of micro parts that are micro endo-scope, PDA, and tele-communication had been extended, there are required the micro machine tools and MEMS in order to machining for those parts. In order to machining of the micro parts, the micro machining center is very effective. The micro machining center had some advantages that are lower cost, higher accuracy, and lower required powers than existing machine tools for machining of micro parts. In this study, in order to analyze the machining characteristics and its application possibility of the developing micro machining center with 60,000rpm rotations, 0.1$\mu\textrm{m}$ resolutions, and 80 50 50mm sliding unit, the machining experiment had been executed. In this experimental machining, 0.1~ 0.5mm endmills are used to machining the micro cap and tele-communication's parts. In the future, experimental results will be adapted to the micro-machining center.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.934-937
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• 2001

It is well-known that the micro fabrication technology of micro parts are the high energy beam or silicon-based micro machining method such as LIGA Process, Laser machining, photolithography and etching technology. But, for fabricating complex 3-D structure it is better to use mechanical machining. This machining method by the mechanical machine tool with nanometer accuracy is getting attention in some field-especially micro optics machining such as grating, holographic lens, micro lens array, fresnel lens, encoder disk etc.. In this study, we survey the micro fabrication by mechanical cutting method and set up the mechanical micro machining system. And we carried out micro cutting experiments for micro parts with v-shape groove.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.501-502
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• 2006

In-plane type micro piezoelectric micro grippers with pneumatic lines for manipulation biological cells and micro parts were designed, fabricated, and characterized. Micro grippers were fabricated through the final micro-sanding process after wafer level bonding between the etched 4' Si wafer with pneumatic channels and 4' glass wafer. Displacements between two jaws of fabricated micro grippers were linearly increased with applying voltages to piezoelectric actuator. In the case of applying 80 V, the displacement between two jaws was $160{\mu}m$. Using fabricated micro grippers, manipulation tests for biological cell and micro parts with the sizes less than $100{\mu}m$ are in process.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.181-184
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• 2002

In these day, fabrication technologies for micro parts become more important with the increase of interest on microsystem and developed through the various approaches in the whole world. Among these technologies; micro mechanical machining is one of the most effective methods for the fabrication of micro parts. In this study, we fabricated micro shafts using micro endmill and micromachining system and measured the cutting force at the process. Also, Based on the data, we simulated the deformation of micro shafts due to the cutting force. Through the simulation results, it was verified that the cutting force at the process is enough to cause dimensional error at the micro shafts.

• 한국공작기계학회논문집
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• 제17권2호
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• pp.121-127
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• 2008

Micro end-milling has been becoming an important machining process to manufacture a number of small products such as micro-devices, bio-chips, micro-patterns and so on. Despite the importance of micro end-milling, many related researches have given grand efforts to micro end-milling phenomenon, for example, micro end-milling mechanism, cutting force modeling and machinability. This paper strongly concerned actual problem, micro tool deflection, which causes excessive machining errors on the workpiece. To solve this problem, machining error prediction method was proposed through a series of test micro cutting and analysis of their SEM images. An iterative algorithm was applied in order to obtain corrected tool path which allows reducing machining errors in spite of tool deflection. Experiments are carried out to validate the proposed approaches. In result, remarkable error reduction could be obtained.

• 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.