本文考慮不同擋板高度、擋板數與注入位置的側注入混合器，由觀察暫態過程，來探討它們對混合效果之影響。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）翻模製作微型混合器，接合流道上蓋，即完成微型混合器，接上矽膠管，再加上兩個微量式注射幫浦構成完整系統。影像擷取系統為數位攝影機、光學顯微鏡、影像擷取卡與電腦，紀錄流體在流道中流動與混合情況，並以影像軟體擷取出圖片，將呈現其暫態過程。另外，利用熱流數值模擬軟體(CFD-ACE+)模擬計算流場狀態。結果顯示：(一) 當擋板高度愈高，其混合效率愈佳，(二) 混合效果會隨擋板數目增加而較佳，但是改善幅度隨著擋板總數的增加而減少，(三) 擋板數必須達到三擋板才能有較佳混合，(四) 側壁注入必須錯開才會有較佳的混合效果。

In this work, we investigate the effects of baffles and sidewall injection on the efficiency of mixers by studying the transient process. In fabrication, the SU-8 thick film photoresist is used to fabricate the structure of the micromixers on the silicon wafer by photolithogrphy. Casting of polydimethysiloxane（PDMS）is followed to mold the SU-8 pattern. We bond the first patterned PDMS with a cover layer of PDMS. Then, we obtain the experimental micromixer. The fluid flow system consists of the micromixer with pipes and two micro-syringe pumps. An image capture system, including a CCD camera, an optical microscope, an image capture card and a personal computer, is set up. The visualization of the mixing process of the mixing fluids are obtained by the system. Then, we use image software to obtain pictures showed the transient process. Besides, the commercial codes, CFD-ACE+, are applied to simulate the transient mixing. The results show that (i) the baffles are higher, the mixing is better, (ii) the efficiency increases with the number of the baffles, but the improvement of the efficiency decreases as the number of baffles gets large, (iii) to enhance the mixing of fluids, three or more baffles are needed, (iv) the mixing by staggered injections is better than that by in-line injections.

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