矽膠材料被動式微流體混合裝置之設計與性能分析

Abstract

在一些生化反應中，微混合器的重要性在於混合的好壞決定了整個反應系統效率之優劣，因為不完全的混合會嚴重地影響要完成的反應。在微小尺度下，流體會以層流的方式流動，因此很難達到混合。在此，我們提出一個新型的混沌混合器，利用微機電系統製程技術及配合聚二甲基矽氧烷(PDMS)製作出結構簡單，並能增加混合效率之被動式微混合器。此混合器利用上下交叉型阻礙物、X型溝槽及X型阻礙物之結構，使得流體在低雷諾數時能產生混沌移流並探討三種混合器在不同雷諾數下對於混合效果的影響。通常來說，混沌移流可以靠著改變特殊的流道形狀或輸入外力而產生；本研究中並配合CFD-ACE(U) Modules軟體模擬分析，模擬結果與實驗結果相互比較。 針對本研究中設計製作之微混合器，實驗的結果顯示上下交叉型混合器具有最好的混合效果，其在雷諾數為50時，混合指標可以達到82%。

The importance of micromixers for microreaction technology demands some well-founded knowledge on the mixing behavior of these devices, since the flow in a micro-channel is laminar which makes mixing quite a difficult task to complete. In this study, we present a new chaotic mixer. In experiment, MEMS fabricated passive micro-mixers with cross obstacles, X-type grooves, and X-type obstacles by polydimethylsiloxane (PDMS) micro-mixer are considered, which lead to chaotic advection at low Reynolds number and also enhance fluids mixing. The influence of various Reynolds number to the three micromixers on the mixing efficiency is examined. Generally, chaotic advection can be generated by special geometries or induced by an external force. In addition to the experiment, CFD-ACE(U) Modules Software for simulating analysis on the mixing process is also performed and compared to experiment. Experimental results show that cross obstacles micro-mixer has great mixing efficiency and the mixing index will increase 82% when the Reynolds number is about 50.