微型檢測裝置將懸浮粒子由微流道運送到感應器，檢測前須透過微流體進行粒子聚集。本論文探討在矩型微流道內懸浮粒子的聚集問題，並提出利用電滲流的調整來進行回饋控制的策略。
本論文推導出矩形微流道內電滲流的流線函數解析解，可允許封閉區域及任意滑移速度分布之邊界條件。此解為ㄧ無窮級數展開式，由符合封閉條件之特徵函數組成，展開式係數須滿足邊界滑移條件。然而展開式係數的難收斂性容易造成其計算值的不正確，以及解析解在邊界附近收斂性不佳。為解決此困難，將展開式係數分解成難收斂和易收斂兩部分，在特定滑移速度分布下，利用難收斂部分的週期性來計算其值，進而輕易獲得易收斂部分的準確值。
電滲微渦流和短距力可形成表面停滯點，產生粒子在該點聚集的效果，但微渦流中心附近粒子脫離困難及電滲流輸送路徑過長，使得聚集效率不佳。本文利用推導的解析解來模擬粒子聚集的回饋控制問題。所提之回饋控制策略結合基本微渦流和短距力，以接近微渦流中心之粒子作為控制對象，選擇不同位置作為虛擬目標點，最終達到粒子於停滯點的快速聚集。

Micro sensing devices deliver suspended particles to sensors through microchannels. Prior to sensing, the particles should be assembled by microfluid. This thesis investigates the assembly of suspended particles in rectangular microchannels and proposes a feedback control strategy based on the adjustment of electroosmotic flow.
The thesis derives an analytical solution for the stream function of electroosmotic flow in a rectangular microchannel, which allows the boundary conditions of a confined region and arbitrary slip velocity distributions. The solution is an infinite series expansion and is composed of eigenfunctions that confine fluid flow. The expansion coefficients must satisfy the boundary slip conditions. However, the expansion coefficients are difficult to converge, causing inaccuracy in calculating their values as well as poor convergence of the analytical solution in the vicinity of the boundaries. To solve this difficulty, each expansion coefficient is divided into a difficult-to-converge part and an easy-to-converge part. For specific slip velocity distributions, the periodicity of all difficult-to-converge parts can be identified and their values can be calculated. As a result, the accurate values of the easy-to-converge parts can be obtained easily.
Electroosmotic microvortices together with short-range force could form a stagnation point on a surface to create the effect of particle assembly at that point. However, the efficiency of particle assembly is often not high because of the difficulty for particles escaping from the center of a microvortex and long travelling paths via electroosmotic flow. This thesis applies the derived analytical solution to simulate the feedback control problem of particle assembly. The proposed feedback control strategy combines the fundamental microvortices and short-range force, employs particles close to the centers of microvortices as the controlled objects, and chooses different points as virtual targets. Eventually, the control strategy can achieve fast particle assembly at the stagnation point.

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