微囊胞產生與交流電場操控

Abstract

本論文成功的利用震盪法及微流道製做出直徑為數微米至數十微米的油相微囊胞 (Emulsion)或水相微囊胞，並利用交流電電場完成液態微囊胞的極化現象，同時也在以油相為連續相的水相微囊胞中摻雜黑色染料製作出帶有顏色之液態微囊胞。 實驗中，選擇以1 cSt黏滯度的矽油(Silicone oil)作為分散相(油相)，另一方面在水相中加入2 wt%的界面活性劑SDS (Sodium dodecyl sulfate)，之後將油相及水相以1比4的體積百分比混合，並放置於試管震盪器上利用震動產生出數微米至數十微米的油相微囊胞；接著我們再將製作出的微囊胞放置到間隔200 □m的兩平行板電極之中，並成功的產生出電場極化效果。除此之外，我們也嘗試以不同流速比之流體於實體微流道製作出約5-10 □m水相微囊胞，並以低於8.6 VRMS，300 kHz之電壓成功產生極化之現象，使用低濃度的水相微囊胞時，可以明顯的觀察到鏈狀結構，而高濃度的水相微囊胞則可以在電場中產生孔隙狀結構，最後我們更在非均勻的電場中觀察到微囊胞的濃縮亦或是微囊胞破壞現象。

In this study, we successfully fabricate aqueous/organic or organic/aqueous emulsions by ultrasonic vibration and PDMS microchannel, and the emulsions were polarized by an AC electrical flied. In addition, the aqueous droplets containing black dye were produced in organic phase for polarization. For emulsion fabrication, we choose 1 cSt silicone oil as continuous phase (oil phase) and choose DI water with 18 mM SDS (Sodium dodecyl sulfate) as dispersed phase (aqueous phase). The volume ratio of oil to water was 1:4; the mixture was shaken by ultrasonic vibration to form 1 □m to 30 □m oil-emulsions. Then the emulsions were dispensed between two parallel plates which were spaced 200 □m apart and got the polarized phenomenon of emulsions successfully. Furthermore, we fabricated radius of 5-10 □m water emulsion by microchannel at different flow rate and polarized it successfully. The applied voltage is lower than 8.3 VRMS at 300 kHz. We can observe the chaining structure at low emulsion concentration and the honeycombed structure at high emulsion concentration. Finally, destruction and aggregation of emulsion were found under non-uniform electric field.