對於分子化學與生醫實驗中，快速與均勻的檢體混合是非常重要的。本研究設計一種快速混合的被動式微型混流器，在主流道上、下設計微溝槽結構，造成主流道中產生側向迴旋流之現象，以提升混合效果。研究初期使用數值模擬軟體COMSOL 4.3b分析不同溝槽角度、寬度、深度、排列方式及主流道深寬比對於流體壓力場、濃度場及混合效率之間差異性關係，由模擬結果中找出最佳化幾何設計之模型。此微型混流器製程利用微铣削加工機在聚甲基丙烯酸甲酯(PMMA)基材上製造母模，再以聚二甲基矽氧烷(PDMS)為材料翻製出晶片結構主體，最後透過常溫常壓射頻電漿進行PDMS之表面改質，並將兩片PDMS互相黏合，以完成微型混流器之製作。在實驗驗證方面，分別使用食用色素、酚酞化學反應及螢光在立體顯微鏡及雷射共軛焦顯微鏡，來探討混流器之定性定量評估。由2D實驗結果顯示(1)在立體顯微鏡下觀察，在15 mm混合長度中，被動式混流器的混合效率可達90%。(2)當入口流速較慢時，兩檢體之間擁有較長的擴散時間，因此有較佳的混合效率。(3)混流晶片在流道上方溝槽與下方溝槽之間有錯位(misalignment)的情況，導致有較差的混合效率。(4)在較高流速下，上、下溝槽之間的錯位(misalignment)，會進一步的降低混合效率，呈現較差之情況。3D共軛焦掃描螢光實驗的結果與數值模擬及其他實驗的結果差距甚大，可能是因為共軛焦顯微鏡拍攝之動作屬於動態的混合現象。

A micromixer is extremely important to any integrated microfluidic system, and it is very challenging to achieve rapidly uniform mixing performance in the regime of laminar flow with a low Reynolds number. A chaotic advection type micromixer was developed with the double-layer strips on the microchannel wall, which generated two-layer vortices, enlarged contact interface and increased diffusion flux between the mixing reagents, and led to a better mixing performance. Since the physical design of the strip structure is critical to the performance of a micromixer, a numerical simulation software was used to optimize the dimension of the trip and microchannel. Once the design was finalized, a micromilling machine and PDMS casting technique were used to fabricate microfluidic devices for experiments. Multiple experiments were conducted with different equipments and different reagents, and results. 2D show that: (1) this passive micromixer can achieve around 90% M.P. with a channel length of 15 mm from the inlet at three flowing velocities, (2) slower flowing velocity of mixing reagents had higher M.P. due to the longer diffusion time between the mixing reagents, (3) the misalignment between the top and bottom micro strips caused a lower M.P., (4) the damage of misalignment between the two-layer strips to the M.P. is deteriorated at a higher flowing velocity. The 3D experiment results with a confocal microscope is different from the results of simulations and other experiments, which might be due to the in suitability of the confocal microscope for the dynamic mixing phenomena.

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