Analysis of Capillary Flow in Open-Top Rectangular Microchannel

초록:소형분석시스템에서미세채널의상판이제거되면상판에의한빛에너지손실이대폭감소되어광학측정법으로대상을분석할때장점을갖는다. 본연구에서는상판이없는사각단면미세채널내액체유동을이해하려는목적으로실험과전산유체역학해석을수행하였다. 개방형사각단면미세채널에서입자추적기법으로유속을측정하였고, 채널의단면적변화에따른모세관유동현상을이론적으로해석하였다. 단면의너비와높이가각각20 μm로제작된미세채널의주입부에물을떨어뜨렸을때물은오직모세관힘에의해미세채널을따라이동하였다. 액체의젖음현상에영향을미치는중요한유동파라미터는채널의크기와표면장력, 점성등으로볼수있으며, 미세채널에서액체유동을조절하는데이용될수있다.Abstract: Our study aims to understand the flow of liquid in an open-top rectangular microchannel that canbe used in micro total analysis systems (μ-TAS) because it has advantages in terms of light transmission andenergy efficiency. We measured the liquid velocity using particle tracking technique and conducted asimulation with computational fluid dynamics by altering the area of channel cross section and channel lengthfor the capillary-driven flow in the open-top rectangular microchannel. When liquid water drops to anentrance of the fabricated microchannel with a height of 20 μm and a width of 20 μm, it flows along themicrochannel by only capillary force. In the wetting behavior of the liquid, important parameters of this floware channel size, contact angle and liquid properties such as surface tension and viscosity, which are used tocontrol the flow of liquid in the microchannel.