在本研究中，主要為架設一微流道量測系統，並且使用微機電製程技術，製作出微流道晶片提供測量流道中壓降與雷諾數關係，證實在流道水力直徑縮減至100μm左右時，流場仍然適用古典流體力學理論(對層流、液體而言)分析，即流道壓降與雷諾數呈現正比關係，並且證實系統的準確度。
其次，我們利用PDMS翻模製程，在微流道之中設計各種不同尺寸之微小結構，並且在流道上覆蓋鐵氟龍使表面成為疏水性，企圖使液體與流道壁面之總接觸面積下降，從而改善微流道的流阻，經過測量發現微結構在尺寸間距與流量較小時，具有降低微流道壓降的能力。為此學生提出一個合適的理論模型，説明當結構間距縮減到一定尺寸之後，由於壁面疏水性的影響，以及水的表面張力作用，使流體不會滲入微結構的間隙之中，因此流體和壁面的總接觸面積下降，水力直徑提高，流阻變小。最後，將此理論推廣至其他尺寸的微流道中，發展出一套能夠有效降低微流道流阻之微結構尺寸設計方式。

In this study, we established a micro-channel detection system to detect characteristics of micro-flow. The testing micro-channel chips which were made by Micro-Electro-Mechanical Systems (MEMS) were used to find the relation between pressure drop and Reynolds number. We find that with hydraulic diameter decreasing to 100μm the water flowing in a micro-channel can be analyzed by classical hydrodynamics, meant that Reynolds number and pressure drop are direct proportion.
Then, we used PDMS demolding fabrication to get a micro-channel with microstructures on its sidewall, and got hydrophobic surfaces by coating Teflon, attempted to decrease total liquid-solid contact area in the micro-channel. It results that flow resistant of the micro-channel is decreased. According to our measurement, flow resistant of a micro-channel at low flow rate and low width microstructures on its sidewall decreased clearly. In order to explain this phenomenon, we created a new theory: water won’t leak into gaps of microstructures because of hydrophobic surface and surface tension, resulting that total water-solid contact area decrease and flow resistant of the micro-channel decrease too. Finally, a method which can calculate size of microstructures to satisfy pressure drop decreasing condition with different kinds of micro-channels is proposed.

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