• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2007년도 추계학술대회
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• pp.51-54
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• 2007

The induced-charge electroosmosis (ICEO) is a kind of electroosmotic flow which is generated by the electrical charge induced by an externally-applied electric field. That kind of electrokinetic phenomenon provides a nonmechanical technique to handle microscale flows and particles. In this work, we report that the ICEO-like flow is observed around two kinds of circular-cylindrical rod submerged in a dielectric liquid. The conductivity of the solution is varied by adding a surfactant. The flow field is visualized by the PIV method, and average flow speed shows a remarkable dependence on electrical input frequency. Interestingly, the characteristics of the flow are quite different from the conventional ICEO with respect to the flow direction and the locations of center of vortices.

• 대한기계학회논문집B
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• 제35권4호
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• pp.385-390
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• 2011

본 연구에서는 미세채널과 나노채널의 교차부에 불균형 동전기성을 이용한 미세혼합기를 개발하였다. 채널 내 용액의 혼합은 인가된 전압에 의한 전기삼투유동과 미세채널과 나노채널 교차 부에서의 불균형 동전기성에 의한 와류현상에 의해 이루어진다. 미세채널은 PDMS 을 이용하여 소프트리소그래피 공정으로 제작하였고, 나노채널은 미세채널의 특정위치에 전기적 충격에 의한 PDMS 의 파괴로 매우 간단하게 제작하였다. 혼합성능을 평가하기 위하여 형광물질인 Rhodamine B 용액을 이용하여 혼합 전과 후의 형광 분포를 분석하였으며, 약 90%의 혼합을 얻을 수 있었다. 본 연구의 미세혼합기는 복잡한 공정을 요구하지 않고 매우 간단하게 제작되었으며, 생화학시료 분석을 위한 미세시스템에 활용될 수 있다.

• 멤브레인
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• 제27권5호
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• pp.399-405
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• 2017

계면동전위라 불리는 제타전위(zeta potential)란 표면 전하적 특성을 정량화 한 값으로 전기동역학적 현상으로 발생하는 전위차를 말한다. 제타전위는 막오염(fouling)과 표면전하 분석을 통한 개질 확인 및 치환기 확인에 대한 연구가 활발히 진행되어 왔다. 그리고 제타전위를 측정하는 방법으로는 전기영동(electrophoresis), 전기삼투(eletrosmosis), 유동전위(streaming potential)를 기초로 개발되었고, 그중에서도 평막은 유동전위 측정이 적합하다고 알려졌다. 따라서, 본 연구에서는 poly(styrene-ethylene-butylene-styrene) 고분자에 암모늄을 도입하여 아민화된 SEBS 평막 형택의 분리막을 제조하고, 계면동전위 측정기를 이용하여 제조된 분리막들의 유동전위를 측정하여 결과를 분석하였다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2006년도 추계 학술대회논문집
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• pp.163-166
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• 2006

This paper presents numerical results of fluid flows and mixing in a microfluidic device for AC electroosmotic flow (AC-EOF) with coplanar electrodes on top and bottom walls. Differently from previous EOF a channel which attached a couple of coplanar electrodes can be utilized to mix a target liquid with a reagent. In this study we propose a method of controlling fluid flows and mixing enhancement. To obtain the flow and mixing characteristics, numerical computations are performed by using a commercial code, CFX10. It was found that the flow near the coplanar electrodes is of 3-D complex flows and vortices between the other electrodes, and as a consequence the AC-electroosmotic flow on the electrodes plays an important role in mixing the liquid.

• 대한기계학회논문집A
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• 제32권10호
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• pp.831-835
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• 2008

We present a continuous electrical cell lysis chip, using a DC bias voltage to generate the focused high electric field for cell lysis as well as the electroosmotic flow for cell transport. The previous cell lysis chips apply an AC voltage between micro-gap electrodes for cell lysis and use pumps or valves for cell transport. The present DC chip generates high electrical field by reducing the width of the channel between a DC electrode pair, while the previous AC chips reducing the gap between an AC electrode pair. The present chip performs continuous cell pumping without using additional flow source, while the previous chips need additional pumps or valves for the discontinuous cell loading and unloading in the lysis chambers. The experimental study features an orifice whose width and length is 20 times narrower and 175 times shorter than the width and length of a microchannel. With an operational voltage of 50 V, the present chip generates high electric field strength of 1.2 kV/cm at the orifice to disrupt cells with 100% lysis rate of Red Blood Cells and low electric field strength of 60 V/cm at the microchannel to generate an electroosmotic flow of $30{\mu}m/s{\pm}9{\mu}m/s$. In conclusion, the present chip is capable of continuous self-pumping cell lysis at a low voltage; thus, it is suitable for a sample pretreatment component of a micro total analysis system or lab-on-a-chip.