本研究設計一單迴圈方形瑞士捲形狀的微形結構，並針對此結構作不同的修改以探討流道之幾何形狀的改變對混合效果的影響。製程中利用SU-8厚膜光阻及微影製程在矽晶圓上製作微混合器之母模，再以液態聚二甲基矽氧烷(polydimethysiloxane，PDMS)翻製微混合器之流道部分及上蓋部分，將兩者接合後即完成實驗所需的微混合器。在實驗上再加上矽膠管與ㄧ個微量式注射幫浦構成系統，使流體能隨著時間被穩定地輸送至微混合器內。此外，本研究利用包含光學顯微鏡、數位攝影機、影像擷取卡及電腦的影像擷取系統將流體在流道中的流動情形拍攝下來。在模擬上本研究使用熱流數值軟體(CFD-ACE+)計算流場狀態，結果顯示:(一) 在高雷諾數下，單迴圈方形瑞士捲混合器的混合效果比T形混合器的好，(二) 就所設計的四種混合器(單迴圈方形瑞士捲、轉角修圓單迴圈方形瑞士捲、內置阻塊單迴圈方形瑞士捲，縮放流道單迴圈方形瑞士捲混合器)中，以縮放流道單迴圈方形瑞士捲混合器的混合效果最佳，且其展開角越大，混合效果越佳，(三) 迴圈數越多，混合器的混合效果越好。

In this work, we design a single-round squared Swiss roll micro structure and a series of variations of the structure to investigate the effects of the changes of geometry of channels on the mixing. In fabrication, the SU-8 thick film photoresist on the silicon wafer is used to fabricate the master mold of micromixer by photolithography and a first patterned PDMS and a top layer one were molded by casting polydimethysiloxane(PDMS) onto the master mold. After bonding both of them, we obtained the experimental micromixer. In experiment, pipes, a micro-syringe pump and the micromixer comprised a system to make the fluid flow being injected into micromixer steadily with time. In addition, an image capture system, including an optical microscope, a CCD camera, an image capture and a personal computer, was used to capture the visualization of the flow field within the channel. We use the commercial codes, CFD-ACE+ to simulate the flow field. The results show that (i) the single-round squared Swiss roll mixer has better mixing performance than the T-shaped one in high Reynolds number, (ii) in four kinds of mixing devices designed with single-round microchannel (single-round squared Swiss roll, rounded-corner single-round squared Swiss roll, obstruction-in-channel single-round squared Swiss roll and shrunk-expanded-channel mixer), the fourth one has the best mixing performance and the larger the expanded angle(θ) is, the better the mixing performance is, (iii) the mixing performance of multi-round version of Swiss roll mixer is better than that of the single-round ones.

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