Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/1893
標題: 具電場干擾微流道物質混合效益之研究
Study on Species Mixing in Microchannel Flows Subject to External Electrical Excitations
作者: 林宇軒
Lin, Yu-Shan
關鍵字: Mixing;混合
出版社: 機械工程學系
摘要: 
本研究之總體目標為發展主動式之微流體快速混合裝置,藉由改變電極之設計以及隨著時間改變干擾電場,設計兩種主動式混合,分別為具有電場干擾之微混合器與交替電場驅動之微混合器。具有電場干擾之微混合器主要探討在壓力驅動之混合器中,外加電場之波形以及電壓振幅及頻率等,對物質混合增益之情形。交替電場驅動之微混合器則以電動力驅動流體在混合器中之流動,探討週期性外加電壓,對物質混合之影響。本文擬先利用計算流體力學工具CFD-ACE+,先行模擬電場分佈、流體於混合器中之流動方向以及物質於流道中之擴散情形,並藉此數據計算混合效果。為了驗證數值模擬結果之正確性,本研究亦進行實驗量測。混合器的製作是以負光阻(JSR)作為流道結構,工作流體為碳酸鈉和碳酸氫鈉之水溶液作為緩衝液,使用在緩衝液中加入螢光劑做為物質混合觀測之檢測液,藉由螢光顯微鏡觀察流體混合的現象並將拍攝的影像做量化分析,以進行混合效益的探討。研究結果顯示具有電場干擾之微混合器,施加正弦波電場的混合效果會比施加方波電場的混合效果還要好,且其混合效果隨著電壓振幅增加而上升,實驗數據亦獲得一致之結果。在交替電場驅動之微混合器,交替頻率改變跟無交替頻率相比較,會有些許提升混合效果,其混合效果不僅與交替頻率有關,外加電壓之大小對混合效果,亦有很大之影響。

In this research, two micromixers are proposed using external excitations. The mixers have simple T-shaped microchannel incorporated with two types of electrode designs. In the first case, two pars of electrode are placed along the wall of the outlet branch of T-shaped channel on staggered arrangement. Species mixing is a channel by applying time-dependent square and sinusoidal voltages through the electrodes with various amplitude and frequencies. In the second mixer, the applied voltages in traditional electroosmotic flow is changed to be time-dependent square waves. Species mixing is then expected to be enhanced due to flow disturbance. Both numerical and experimental investigations are performed using high voltages and frequencies for the first mixer design: in contrast to the first mixer, the second mixer show that better mixing efficiency can we obtained at low excitation frequencies.
URI: http://hdl.handle.net/11455/1893
Appears in Collections:機械工程學系所

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