介電泳力應用於酵母菌細胞與奈米碳管分離

Application of Dielectrophoresis on the separation of Yeast Cells and Carbon Nanotubes

梁程皓(Cheng-Hao Liang)

指導教授 ： 魏哲弘

大同大學/工程學院/機械工程學系所/碩士(2008年)

摘要

介電泳力由不均勻電場所產生，可用來分離不同介電性質粒子。藉由此介電 泳理論，我們利用微流體晶片分離酵母菌細胞並且鑑定多壁奈米碳管的電性。在 酵母菌分離實驗，利用漸開指叉型電極，活或死酵母菌會受到正或負介電泳力吸 引達到分離效果。實驗結果顯示，使用介電泳力收集酵母菌細胞，正介電泳力收 集的活酵母菌細胞，其效率為91.8% ，而負介電泳力的死酵母菌收集效率為77.9%. 此高收集效率是由於正介電泳力在高頻所產生之介電泳力較強的緣故。 介電泳力的另ㄧ項應用為辨別細胞或無殼粒子的電性。本論文應用介電泳力 將多壁奈米碳管純化，使用三角指叉型電極，其電場強度之極值可由數值模擬得 到。而介電泳頻譜可以透過不同頻率下的正負介電泳符號建立。多壁奈米碳管電 性將可利用此頻譜辨識。奈米碳管微結構及其電性並由拉曼光譜和I-V 曲線驗 證。結果顯示，正介電泳力收集之多壁奈米碳管，其導體成份較多，而負介電泳 力，其導體成份較少收。這種方法可應用於奈米碳管純化以及辨認奈米碳管電性。

關鍵字

介電泳 ； 酵母菌細胞 ； 多壁奈米碳管

並列摘要

Dielectrophoresis (DEP) is a phenomenon resulted from the inhomogeneous
electric field and has been used to sort out colloids with different dielectric properties.
Based on DEP theory, we fabricated a microfluidic chip to sort out yeast cells and
identify the electric properties of multi-walled carbon nanotubes. For yeast cells
separation, a divergent interdigitated electrode was employed and the viable and dead
cells were separated via positive and negative DEP force. The results show the
collection efficiency for viable cells collected by positive DEP is 91.8% and the
efficiency for dead cell collected by negative DEP is 77.9%. The high collection
efficiency from positive is due to the high DEP force which is frequency dependent.
Another application for DEP is its ability to characterize the electric property for
cells and colloidal particles. In this thesis, we use DEP to purify the contents of
multi-walled carbon nanotubes (MWCNTs). An interdigitated triangular electrode was
fabricated where the maxima and the minima of the electric field is easy to identify by
numerical simulation. The DEP frequency spectrum was established by operating
different frequency where the sign of DEP is obtained. The different electric property of
MWCNTs will be sorted accordingly. The microstructure and electric property of the
unsorted, positive DEP sorted and negative sorted samples of MWCNTs were examined
by Raman spectra and I-V curves, respectively. The positive DEP sorted MWCNTs
were more conducting and negative DEP sorted is less conducting. This procedure can
be applied for purification and identification of electrical property of MWCNTs.

並列關鍵字

yeast cell ； multi-wall carbonnanotube. ； dielectrophoretic

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