氣體輔助熱壓技術與陽極氧化鋁結構之應用製作三維流道

隨著微流體系統尺寸的縮小流阻劇升，當流道壁面具備疏水性時，可提升流體之滑移長度，增加流體之流速。假若能製作疏水結構於流道表面取代疏水塗層，將可避免對於生物晶片之影響，藉由降低滑動邊界層效應，降低流體之流阻。目前只能在平面或曲率較大之曲面製作微結構，無法成功製作微結構於流道側壁。本研究使用陽極氧化鋁微奈米複合結構作為疏水結構模具，並使用氣體輔助熱壓與氣體輔助熱成型之製程成功將表面結構與流道結構進行結合，經澆鑄PDMS，再經接合，就可得到三維微流道。本研究首先將99.7%純度之鋁片以陽極氧化處理，得到微奈米複合結構，經電鑄為鎳模，以氣體輔助熱壓製程將此微奈米複合結構製作於聚碳酸酯薄膜(PC film)表面。接著使用此具微奈米複合結構之PC薄膜作為基材，進行氣體輔助熱成型製作流道形貌，流道寬500 μm，深200 μm，其母模以微影蝕刻及電鑄製作，再以PDMS澆灌此具有表面微奈米複合結構及流道結構之PC薄膜模具，得到三面皆具有疏水結構的PDMS微流道。同時以PDMS澆鑄在微奈米結構PC膜上，取得上蓋，將上蓋與流道以大氣電漿接合，得到密封之三維疏水微流道系統。為探討本實驗所製作出之三維疏水流道性能，將進行疏水性及流速之量測比較，證實本實驗所製作疏水流道之性能，其接觸角成功由119 °提升至140 °，而於固定壓力源下，流體在具有疏水結構之微流道系統的流速較沒有疏水結構的提升24.8 %。

關鍵字

疏水流道；氣體輔助熱壓；氣體輔助成型；陽極氧化鋁；疏水性

並列摘要

Microfluidic channel with micro/nanostructures on four walls can change flowing behavior and enhance mixing performance due to apparent fluid slip at hydrophobic walls. Micro/nanostructures, however, cannot easily be patterned on sidewalls by lithography approaches. Hot embossing methods were reported to fabricate micro/nanostructures on channel with aid of PDMS stamp or spin-coated PDMS thin film to prevent nano-structures from damage during forming micro-structures. There are problems in patterning corners due to the elastic recovery of PDMS. In this study, gas-assisted hot embossing and thermoforming processes are employed; nanostructures can be replicated and preserved with gas-pressing technique. Besides, inexpensive anodic aluminum oxide (AAO) sheet is to be used as template for fabricating micro/nanostructures. Through gas-assisted hot embossing and thermoforming processes, PC (polycarbonate) films with micro/nanostructures can be fabricated. After cast into PDMS channel and cover plates, their hydrophobic characteristics are verified. The contact angle of water drop has increased from 119 ° to 140 °. They are to be bonded after plasma treatment. Flow tests are performed to compare the flow rates in microfluidic systems with hydrophobic and plain channels. The flow rate in hydrophobic microchannels has increased 24.8% under the same pressure.

並列關鍵字

anodic aluminum oxide ； gas-assisted hot embossing ； gas-assisted thermoforming ； 3D channel ； hydrophobic

參考文獻

[25] 朱健誠, "V型微流道壓降行為之研究," 中原大學, 2003.

[2] C. H. Choi, K. J. A. Westin, and K. S. Breuer, "Apparent slip flows in hydrophilic and hydrophobic microchannels," Physics of fluids, vol. 15, p. 2897, 2003.

[3] D. C. Tretheway and C. D. Meinhart, "Apparent fluid slip at hydrophobic microchannel walls," Physics of Fluids, vol. 14, p. L9, 2002.

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[5] J. Ou, B. Perot, and J. P. Rothstein, "Laminar drag reduction in microchannels using ultrahydrophobic surfaces," Physics of fluids, vol. 16, p. 4635, 2004.

國際替代計量

氣體輔助熱壓技術與陽極氧化鋁結構之應用製作三維流道

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