臺灣博碩士論文加值系統

有別於傳統使用機械式幫浦來驅動流體，微流體系統常常使用外加交流電場來驅動流體。本論文研究對稱形交流電極設計，所形成的微渦流可將流體中的懸浮粒子收集至電極表面停滯點上，此方法非常適合各種分子、蛋白質、或DNAs的傳送或聚集。
我們分別探討頻率、電壓、邊界條件等因素對微渦流生成和停滯點的影響，實驗發現在頻率100Hz、電壓2.8 Vpp時有最佳粒子聚集效率，從電壓與平均流速的關係證實該流動機制為交流電滲流(ACEO)。此外，經由特殊邊界條件的設計，近一步證實單純的ACEO流動機制便足以在電極上產生停滯點。同時，我們也使用FEMLAB軟體計算各種邊界條件下停滯點位置，得到和實驗數據一致的比較和分析結果。

In microfluidic systems, fluid is usually driven by an external AC electric field rather than a conventional mechanical pump. In this thesis, AC electrodes were designed to generate micro vortices for the assembly of suspended particles onto stagnation points on the electrodes. Such a design is useful for the transport and assembly of various molecules, proteins, and DNAs.
We studied the effects of AC frequencies, voltages, and boundary conditions on the formation of micro vortices and stagnation points. Experimental results demonstrated that the best efficiency of suspended particles assembly occurred at the frequency of 100Hz and the voltage of 2.8Vpp. From the relationship between the applied voltage and the average velocity, it was verified that the flow mechanism was the AC electroosmotic (ACEO) flow. In addition, our specific boundary conditions experiments revealed that pure ACEO flow could give rise to the observed stagnation points. The experimental data are consistent with the simulation results about the position of stagnation points by the FEMLAB software.

目錄

中文摘要
英文摘要
表目錄
圖目錄

第一章 緒論…………………………………………………………1
1.1前言………………………………………………………………1
1.2微機電系統………………………………………………………1
1.3研究動機…………………………………………………………2
1.4文獻回顧…………………………………………………………3
1.5論文架構…………………………………………………………5

第二章 基本原理……………………………………………………8
2.1電雙層形成機制…………………………………………………8
2.2電滲流形成機制…………………………………………………9
2.3對稱形平行電極系統……………………………………………11
2.4等效電路模型……………………………………………………14
2.5停滯點形成機制…………………………………………………15

第三章 微流晶片製作………………………………………………22
3.1電極晶片製作……………………………………………………22
3.1.1電極光罩設計…………………………………………………22
3.1.2玻璃基材清洗…………………………………………………23
3.1.3金屬真空蒸鍍…………………………………………………23
3.1.4光微影製程……………………………………………………24
3.2微流道光微影製程………………………………………………28
3.2.1微流道光罩設計………………………………………………28
3.2.2晶片清洗………………………………………………………28
3.2.3塗佈光阻………………………………………………………29
3.2.4軟烤……………………………………………………………30
3.2.5曝光……………………………………………………………31
3.2.6曝後烤…………………………………………………………32
3.2.7顯影……………………………………………………………33
3.2.8硬烤……………………………………………………………33
3.2.9光阻母模厚度測量……………………………………………34
3.3微流道製作………………………………………………………34
3.3.1材料……………………………………………………………34
3.3.2微流道模型製作………………………………………………34
3.4微流體晶片裝置組合……………………………………………35
3.4.1微流道與電極晶片組合………………………………………35
3.4.2管線組裝………………………………………………………37
3.4.3 PDMS表面改質……………………………………………….37
3.5實驗設備與實驗方法……………………………………………38
3.5.1實驗設備………………………………………………………38
3.5.2實驗溶液與粒子的配製………………………………………39
3.5.3研究方法………………………………………………………40

第四章 結果與討論…………………………………………………51
4.1開放式系統的停滯點觀察………………………………………51
4.1.1頻率對停滯點位置的影響……………………………………51
4.1.2頻率效應之討論………………………………………………55
4.1.3停滯點位置之討論……………………………………………56
4.2封閉式系統停滯點觀察…………………………………………57
4.2.1固定頻率，改變電壓…………………………………………57
4.2.2螢光粒子與電極表面的作用力………………………………60
4.3邊界條件的討論與實驗…………………………………………60
4.3.1水平方向邊界條件……………………………………………61
4.3.2鉛直方向邊界條件(流道高度的討論)………………………63
4.4理論模型與實驗比較分析………………………………………64

第五章 結論與建議…………………………………………………81
5.1結論………………………………………………………………81
5.2改進建議…………………………………………………………81

第六章 未來工作……………………………………………………83
參考文獻…………………………………………………………….84

參考文獻

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[10] Gonzalez, A., Ramos, A., Green, N.G., Castellanos, A. and Morgan, H., “Fluid Flow Induced by Nonuniform AC Electric Fields in Electrolytes on Microelectrodes. II. A Linear Double-Layer Analysis,” Physics Review, E, 61, 4019 (2000).
[11] Gonzalez, A., Ramos, A., Green, N.G., Castellanos, A. and Morgan, H., “Fluid Flow Induced by Nonuniform AC Electric Fields in Electrolytes on Microelectrodes. I. Experimental Measurements,” Physics Review, E, 61, 4011 (2000).

[12] Gonzalez, A., Ramos, A., Green, N.G., Castellanos, A. and Morgan, H., “Fluid Flow Induced by Nonuniform AC Electric Fields in Electrolytes on Microelectrodes. III Observation of Streamlines and Numerical Simulation,” Physics Review, E, 61 4019 (2002)

[13] Garcia-Sanchez, P., Ramos, A., Green, N. G. and Morgan, H., “Experiments on AC Electrokinetic Pumping of Liquids Using Arrays of Microelectrodes,” IEEE Transactions on Dielectrics and Electrical Insulation, 13, 3 (2006).

[14]李孟駿, “以結合流動之介電泳操控次微米粒子運動的實驗探討,” 國立成功大學碩士論文 (2006)。