本文探討被動式微型混合器中，改變流道結構、擋板尺寸以及流體注入位置使流體產生較佳的混合效果。並且利用熱流數值模擬軟體（CFD-ACE+）模擬計算流場之狀態，以供預測微型混合器效率之參考。
　　製程中，採用SU-8厚膜光阻以微影製程在矽晶圓上製作微型混合器之母模；再以聚二甲基矽氧烷（polydimethysiloxane，PDMS）為材料，翻模製作微型混合器，並與流道上蓋接合。最後，檢測混合效率的方式則是用影像軟體分析流道中不同位置之灰階色值，以判定其混合效果。
　　為了研究流道結構對混合的影響，將擋板尺寸、流體之注入位置、入口流速、與混合室長寬比改變，然後比較各種變數對微型混合器混合效率之影響。根據數值模擬與實驗之結果，可以發現擋板的高度與數目會對混合效果產生最大的影響。與其餘之微型混合器相較，本微型混合器結構簡單、易製造。因此，可以推論本微型混合器在雷諾數50以下時，比其他型式混合器更好。

　In this thesis, we investigate a novel passive micromixer for better efficiency of mixing by tuning the structures of microfluidic channels with baffles and side injection. Furthermore, simulating the situation of the flows by software CFD-ACE+ provides the forecast of the mixing efficiency of the micromixer.
　In fabrication, SU-8 thick film photoresist is used to fabricate the mold of the micromixers on the silicon wafer by photolithography. Then, we transfer the mold structure of the micromixer to polydimethysiloxane (PDMS), and bond it with a cover layer of PDMS. Finally, the mixing performance has been demonstrated with an image analyzing software to quantify the gray value distribution in the exit section.
　To study the effect of structure on mixing, we change the size of baffles, the injection positions, the speed of the injected liquid and the length-width ratio of mixing rooms. Then, we compare the effect of those variables on the mixing efficiency of the micromixer. The numerical simulation and the experimental results show that the number and height of baffles dominates the mixing efficiency. Compare with other micromixers, the novel micromixer’s structure is simple and easy to fabricate. Thus, we may conclude that the present micromixers have better performance than others for the cases with Re＜50.

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