本研究利用介電泳在微流體晶片中操控微藻細胞進行分離，探討連續偵測藻油的可行性，我們採取的分離機制為在第一及第二電極對使微藻細胞受到負介電泳力的作用使其可以被導引及排列成一直線，而在第三電極對時讓不同含油量的微藻細胞受到不同程度的負介電泳力的作用使其達到分離之效果。當微藻細胞受到強的負介電泳力作用時會被分離電極對排斥往支流道流動；受到弱的負介電泳力作用時，會受到流體拖曳力(hydrodynamic force)的作用而繼續往主流道移動。我們發現微藻的crossover frequency隨著含油量的增加而上升，首先以300kHz的操作頻率將微藻以電極對排列成一直線，再以較高的頻率來分離不同含油量之微藻，如7MHz分離含油量13%以下和21%以上的微藻，或是10MHz分離含油量24%以下和30%以上之微藻。而透過螢光強度的檢測，可以針對含油量24%以下和35%以上微藻的分離作判別。

In this study, a continuous flow dielectrophoresis (DEP) microfluidic chip was fabricated and utilized to sort out the microalgae (C. vulgaris) with different lipid contents. The proposed separation scheme is to allow the microalgae with different lipid contents experience different negative or no DEP force at the separation electrode pair under the pressure-driven flow. The microalgae which experience stronger negative DEP will be directed to the side channel while those experience less negative or no DEP force will pass through the separation electrode pair to remain in the main channel. It was found that the higher the lipid content inside the microalgae, the higher the crossover frequency. Separation of the microalgae with 13% and 21% lipid contents, and 24% and 30-35% lipid contents was achieved at the operating frequency 7 MHz, and 10 MHz, respectively. Moreover, separation can be further indicated/verified by measurement of the fluorescence intensity of the neutral lipid inside the sorted algal cells.

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