本研究利用微機電系統製程技術之灌注成形法，完成聚二甲基矽氧烷(Polydimethylsiloxane, PDMS)微流體晶片之製備，以應用於同時生成四種不同濃度且均一粒徑的微膠囊之研究。研究策略為利用計算流體力學軟體來模擬微流道晶片內四個微流管道的流速分佈情形，並改變樹狀分流管道寬度設計，以達到微流體晶片於後端產生四管一樣的流速分佈，並藉由微機電製程技術製作實驗所需的微流體晶片。實驗上，在微流體晶片前端分別注入台盼藍水溶液和去離子水，利用微混合器與樹狀分流的設計，均勻混合出四種不同的濃度，並在微流體晶片後端利用鞘流原理來產出四管均一粒徑且具有不同濃度的微乳化球，粒徑分佈範圍介於50.8 ~ 100.5 m之間。之後，將此微流體晶片應用於生成均一粒徑且包覆不同牛血清蛋白(Bovine serum albumin, BSA)濃度之褐藻酸鈣(Ca-alginate)微膠囊的生成上，實驗結果在粒徑分佈範圍可介於59.9 ~ 105.2 m之間。將微流體晶片所生成四種不同BSA濃度的微膠囊置於磷酸鹽緩衝溶液中進行BSA釋放，在經過長時間的紫外光-可見光吸收光譜儀量測，發現此微流體晶片所生成的Ca-alginate，可成功釋放出具有不同濃度分佈的BSA，證明本研究所設計的微流體晶片可應用於同時生成均一粒徑且不同濃度的微膠囊。

In this study, the polydimethylsilcoxane (PDMS) microfluidic chip is fabricated by using MEMS, casting molding, and microimprinting technology. The chip is used to study microcapsules of different concentrations. Our strategy is to simulate the velocity distribution of fluids in different microfluidic channels by using computational fluid dynamic (CFD) software. The results of simulation give us insight on how to design the wide of bifurcate channels and fabricate the microfludic chip by MEMS. The solution is mixed by using the microfluidic network, and via the sheath focusing effect to form uniform water-in-oil (w/o) emulsions with different concentrations. We demonstrate that the size of emulsions can be controlled from 50.8 µm to 100.5 µm in diameter, simply by altering the relative continuous/dispersed phase flow rate ratio. However, the manipulation of Ca-alginate microcapsules, using a microfluidic chip, for the encapsulation of Bovine serum albumin (BSA) with different concentrations is by external gelation methods. The size can be controlled from 59.9 µm to 105.2 µm in diameter, and then the microcapsules are placed in the phosphate buffer saline (PBS) for drug release. Through the UV-Vis spetrophotometry at 280 nm, we demonstrate that the different concentrations of BSA are encapsulated in the microcapsules.

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