微乳化液滴製備技術已廣泛地被應用在各種領域，本研究以微機電技術製作兩種不同設計的微流體乳化晶片，並成功地製作均勻性高之乳化液滴，且其中的一種晶片設計可產生雙重乳化微液滴。第一種新型乳化晶片透過可控制式側壁結構來調整流體聚焦寬度，並且在液體內產生微液滴。其主要結構包含一主動控制微管道寬度機構以及一微切斷器機構，用來調整控制聚焦寬度並產生微液滴。實驗數據顯示，透過注入不同壓力的壓縮空氣到側壁氣室後，可控制改變側壁的變形量，而微管道的寬度隨之改變。透過所提出的機制，樣品流可以被聚焦成更窄的寬度，並且透過此晶片控制產生的微液滴直徑尺寸可以更小。本研究中可以控制聚焦寬度到9μm，並且生成平均直徑約75μm的微液滴，變異係數值在7%以內。本晶片之設計可有效完成高均勻性之微奈米尺寸乳化晶片。
第二種微乳化液滴晶片整合了T型管道乳化技術、微流體聚焦技術與可控制式側壁結構，以產生雙重乳化微液滴。首先在前端T型管道搭配可控制式側壁處，利用流體連續相的剪切力大於分散相的表面張力，拉斷液滴形成油包水（w/o）的乳化液滴，接著後端利用微流體聚焦技術與切斷器側壁結構，在油相與外部水相交會區製作出w/o/w之雙重包覆液滴。實驗結果顯示，此微流體晶片成功製作出顆粒均勻的多重包覆微乳化液滴。藉由側壁結構的變形量，可改變流體的流速，進而改變液滴的尺寸。目前製作的三相微液滴直徑分佈為85μm～165μm，而其對應的內部液滴直徑分佈為60μm～80μm。此一結果驗證了本研究的可行性，更具有實際的應用潛力。
上述兩類新式微流體系統可以在乳液製程、奈米生醫和微液滴上做極為廣泛的運用，使此一技術平台更進一步拓展至生物技術和藥物傳輸的領域。

The formation of micro-scale mono-dispersed emulsions is essential for a variety of applications. This study describes two new microfluidic chips for emulsification using enabling microfluidic technologies. The main feature of these two chips is the capability of generating uniform microdroplets with varied size in liquids for emulsification applications. Briefly, the first study reports a microfluidic device capable of fine-tuning sample flow focusing and generating micro-scale droplets in liquids by utilizing a controllable moving wall structure. This was achieved by the combination of two integrated mechanisms including an active microchannel width controller and a micro chopper, into the microfluidic system. Experimental data showed that the deformation of the controllable moving wall structure can be adjusted pneumatically by applying different air pressure into the air chamber of the moving wall structure so that the width of the microchannel can be controlled accordingly. By utilizing the proposed mechanism, the sample flow could be focused into narrower width and well-controlled micro-droplets with smaller diameter could be generated by utilizing the developed microfluidic device. The sample flow width could be focused into 9 μm and micro-droplets with an average diameter of 75 μm could be generated by utilizing the proposed device with a variation less than 7%. In this study, two chips with parallel and concentric layouts for multiple channel emulsion have been successfully demonstrated.
The second microfluidic chip proposed can also be used to generate well size-controlled double emulsion microdroplets in liquids by integrating three mechanisms including a traditional emulsification process by a T-junction design, micro-flow focusing and the control of liquid flow by the moving-wall design. Briefly, by the combination of these mechanisms of the incorporated T-junction microchannel design and the moving wall mechanism, water-in-oil (w/o) droplets at the intersection of the water phase and the oil phase can be generated. Then, double emulsion droplets (w/o/w) were formed by using the flow focusing and the shear forces acting at the intersection of the oil phase and the external water phase. The experimental results showed that uniform double emulsion droplets were produced in a tunable manner utilizing the deformation of the moving wall structures. The diameters of the outer droplets range from 85μm to 165μm while the sizes of the internal droplets range from 60 μm to 80μm. This result demonstrates the feasibility of using the proposed system for generating size-controlled double emulsion microdroplets. These devices have shown great promise in various applications including emulsification, nano-medicine and droplet-based microfluidics.

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