擁有操控微小粒子，尤其是活細胞的能力，對很多生物學以及醫學的應用是很基本的，這些操控的能力包括隔離或偵測稀少的癌細胞、從稀釋的溶液中聚集細胞、根據細胞特性分離細胞以及抓取且定位單一細胞並加以辨識細胞。因此電學、光學、磁學及力學的方法不僅被廣泛運用在操控細胞的科技上，也被整合到微晶片上用來抓取細胞。本研究的目的在於探討應用介電泳力之原理研發微抓取器。本論文首先搜尋學術界在此方面之研究發現介電泳力廣被接受為細胞分離術之重要機制，而且在分類過程中不會損害供研究之樣品活細胞。在本研究中，藉由CFD-ACE+商用軟體的模擬得知利用低導電度的四角型結構物所產生的無電極式的介電泳力之設計，會將微小粒子抓取在兩結購物中間的區域，使得細胞可以承受不穩定的流場作用。根據模擬分析的結果，得到結購物的幾何外型尺寸、結構物的間距、兩電極板的距離以及施加電壓對介電泳力的影響，更近一步得到結構物的間距、兩電極板的距離、施加電壓以及微小粒子的粒徑對微晶片抓取微小粒子的能力之影響，藉以得到微抓取粒子晶片設計的準則。此研究結果對使用介電泳來做生物分析的系統有顯著的貢獻並建議未來可進一步研究之方向。

The ability to manipulate particles, especially living cells, is fundamental to many biological and medical applications, including isolation and detection of sparse cancer cells, concentration of cells from dilute suspensions, separation of cells according to specific properties, and trapping and positioning of individual cells for characterization. For these purposes, electric, optical, magnetic, and mechanical forces have been widely used not only as conventional manipulation principles, but also as trapping methods to be integrated in microchip formats. This study is an attempt to research on microfluidic trapping by using Dielectrophoresis (DEP) force. The DEP force as trapping mechanism has the advantage of no risk to the sample. The electrodeless dielectrophoretic trapping is composed of conductless tetragon structures in micro-chip. Cells are trapped between the tetragon structures and held against destabilizing fluid flows by dielectrophoretic forces. We have advanced the design of electrodeless DEP geometries, correlated particle acted by DEP effects with electrical-field distributions determined through computer simulations. Parameters as being analyzed the effect on the magnitude of DEP force include the width, thickness, and convergent theta of the tetragon structure, the separate distance of two electrodes, the spacing between two structures, and the applied voltage. In addition, it is important for our design to comprehend the factors containing the separation distance of two electrodes, the spacing between two structures, the applied voltage, and particle radius, as well as analysis their influence on the trapping ability. The relation of maximum flow velocity in terms of electric field and particle size is verified. The outcomes of this study could have a substantial impact on the development of bio-analytical systems using dielectrophoretic forces.

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