• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.8 s.227
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• pp.1159-1165
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• 2004

This paper describes fabrication of a micro cell counter integrated with an oxygen micropump and counting experiment with Sephadex G-25 beads ($70{\sim}100\;{\mu}m$). The pumping part consisted of a microheater, catalyst (manganese dioxide) enveloped with paraffin, hydrogen peroxide, and microchannel, and the counting part consisted of collimated light, a microwindow, and a phototransistor including an external circuit. The micropump generated oxygen gas by decomposing hydrogen peroxide with manganese dioxide, which was initiated by melting the paraffin with the microheater, and pumped beads in the microchannel. When the beads passed the microwindow, they shaded the collimated light and changed the illumination on the phototransistor, which caused the current variation in the circuit. The signals, according to the bead size, reached up to 22 mV with noise level of 2 mV during 50 seconds and the numbers of peaks were analyzed by magnitude.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.515-516
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• 2012

• 순환기질환의공학회:학술대회논문집
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• 2006.10a
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• pp.21-23
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• 2006

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.431-432
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• 2008

• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.257-260
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• 2004

• Proceedings of the Korean Vacuum Society Conference
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• 2004.02a
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• pp.129-130
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• 2004

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.239-240
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• 2011

• Korean Chemical Engineering Research
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• v.50 no.4
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• pp.743-748
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• 2012

This study presents the effects of micro-geometries on the swimming behavior of Pseudomonas aeruginosa. First, we have measured parameters of single-cell motility including cell speed, run duration time, and tumble angle under two dimensional space. The results are used to calculate motility coefficients in the width of microchannels ranging from 10 to $100{\mu}m$. Since the single-cell motility parameters measured depend on the interaction of flagella with the microchannel wall, the duration time of the running cell in restricted geometries is distinctively different. Therefore, the motility of bacteria is decreased by restricted geometries. This study suggests that microfluidic approach is useful tool for the analysis of bacterial motility under the restricted space and rapid analytical tool.

• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.302-307
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• 2004

이 논문은 제한된 대역폭을 가진 고정 채널 할당 문제를 유전알고리즘을 이용하여 최적화하는 방법을 제시한다. 또한 이 논문에서는 유전알고리즘의 미세조정 능력 향상을 위해 지역 최적화 방법을 고안하였다. 고정채널 할당 문제를 행렬로 표현하여 지역 최적화 알고리즘에서는 채널을 수평 또는 수직으로 움직임으로써 유전 알고리즘의 성능 향상을 꾀한다. 제안된 방법은 기존의 방법보다 뛰어난 성능 향상을 나타냄을 실험결과에서 보일 것이다.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.196-201
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• 2001

In this paper, we have described the microchannel fluid behavior in a slot between rotating curvilinear surfaces of revolution using micropolar fluid theory. ]n order to solve this problem, we have used boundary layer equations and applied non-zero values of the microrotation vector on the wall. The results are compared with the corresponding flow problems for Newtonian fluid. Results show that both the velocity distribution and the microrotation component distribution for a micropolar fluid are lower than that of a Newtonian fluid.