本文利用晶格泊松波茲曼法模擬分析在微渠道中二維電滲透流場流體流動之特性。其中分別詳細地討論渠道表面電位、表面性質、離子莫耳濃度、渠道高度與外加驅動力等對電滲流體流動所產生的影響。並且還模擬了在本文全新設計的I字型微渠道中電滲透流之流動特性。本文根據渠道幾何形狀與表面性質分成三個部分來分別詳細討論：
首先，先進行在兩平行長直型平板微渠道中之電滲透流模擬。本文提供一些方法來擾動流體並進而產生渦旋，例如：調整渠道異質性表面電位、外加周期性電場與壓力場之相位角等。並且可以藉由適當的分布配置異質性表面電位在不同的位置而分別在渠道中央與近壁處產生渦旋。然而，渦旋之尺寸大小、結構強度與旋轉方向都可以藉由適當地設定單獨驅動力場之相位角或是聯合驅動力場之相位差來控制。本文提供這些方法來產生渦旋的目的是希望能夠擾亂流體的結構產生類似像障礙物的渦旋以期能夠增加微混合之性能。對於未來微混合器的設計研究提供一些想法。
第二個部分，本文是設計一個尚未有其他研究所討論過的I字型微渠道。而在此微渠道中流體的擾動與流率之控制機制是此部分所要強調研究之主題。在流率控制的部分，本文是利用配置異質性電位並且操控電場強度、單獨驅動力場之相位角與聯合驅動力場之相位差來研究調查渠道中兩接合處之流量比。結果發現流體速度與流率可以藉由輸入適當的相位角與相位差來獲得精確的調整。此外，對於增進流體擾動的部分，可以利用配置異質性荷電極板於渠道各個位置來引發。並且還討論電極板之數量對於微流體的擾動所產生的影響。由單一電極板之模擬個案中，當增加電極板與渠道入口之間的距離可以增加流率比。並且在流動方向上配置對稱的電極板且電位為渠道表面電位的兩倍時會有渦旋的產生。而渦旋之數量可由所使用的電極板之數量來獲得控制。另外，本文還將問題延伸至雙接合管的問題。重要研究結果指出儘管輸入各種不同的相位角，後接合管之流率比幾乎沒有差異，兩接合處之流量是近乎等量的。
最後，我們將針對渠道的表面特徵性質如何影響電滲透流體流動來進行討論。其主要討論的表面特徵有隆起物、孔穴並且設計障礙物於渠道中來研究在I字型微渠道中之流量關係。結果發現流體通過單一隆起物與孔穴時皆會使流量降低。另外，當兩種表面特徵之電位異於光滑表面電位且逐漸增加時，亦會減少流量。當隆起物的高度接近電雙層厚度時對於流量會有較大的變化產生。本研究也模擬當流體流過兩個連續孔穴或者是隆起物與孔穴之組合時對流率所產生的影響。研究結果指出當增加兩種狀況其兩者之距離時皆會使得流量降低。並且更進一步的去討論隆起物與孔穴之前後位置關係。結果發現孔穴位置在隆起物後方時對於流量會有較大的影響。針對這兩種表面特徵，根據研究結果指出隆起物所引起流率的變化較孔穴大。由以上之結果與光滑表面做比較時可以得到一個重要結論，即可以利用調整相位角與相位差的方式來進行流率的精確控制。最後則設計一障礙物於渠道表面上並進行流動之模擬。結果指出當流體流過一個高度與絕對值電位較高的障礙物時皆會減少流量。
綜合以上三個部份的研究結果不但指出表面特徵性質對於微渠道中電滲透流率之重要性，而且證實了具有周期性驅動力場之晶格泊松波茲曼法之優勢。因此，本文的主要貢獻是提供一個簡單的計算方法與驅動方式來模擬在複雜幾何形狀的微渠道中電滲透流之特性。

The characteristics of 2-dimensional (2D) electro-osmotic flow fields are analyzed by applying the lattice Poisson-Boltzmann method to simulate fluid flow in micro-channels. We discuss in detail the influences of surface potential, wall surface properties, ionic molar concentration, channel height, and external driving force fields on fluid flow, and we simulated the fluid flow within a novel I-type microchannel. This study is categorized into three areas.
First, we introduce an alternative scheme for producing vortexes in a straight channel by adjusting the heterogeneous surface potentials and phase angles of the periodic electrical and pressure force fields. By distributing heterogeneous surface potentials at various positions creates vortexes near walls, or in the center of the channel. The size, strength, and rotational direction of vortexes are controllable by setting appropriate phase angles for a single driving force field, or by defining the phase differences between the combined electrical and pressure force fields. These obstacle-like vortexes perturb the fluid and hinder flow, and thus, may be useful for enhancing micro-mixer performance.
Second, we study the perturbed fluid and flow rate control mechanisms in an I-type microchannel. We investigate the flow rate ratio between two junction sections that results from placing heterogeneous potentials in the channel, and from manipulating the electric field strength, phase angle, phase difference between the driving fields. The fluid velocity and flow rate are precisely tunable by inputting appropriate phase angles and phase differences for the driving fields. We also study the perturbations induced by heterogeneously charged plates in the channel. For single plate cases, increasing the distance between the plate and the inlet increases the flow rate ratio. Vortexes form when the potential of symmetrically placed plates is twice the channel potential in the direction of flow. The number of vortexes is controllable by the number of plates used. Placing the symmetrically charged plates on the lateral walls produces stronger vortexes. The flow rate ratio is can be bought to almost unity in channels with single and double junctions by adjusting the phase angle to modifying the flow rate.
Third, we investigate how flow rate is affected by ridges, cavities, and obstacles in the rough channel. The flow rate is reduced over ridges or cavities in the channel, and reduces as the separation distance between a ridge and a cavity or between two sequential cavities is increased. Increasing the zeta potential of these surface features also reduces flow. Placing a cavity behind a ridge produces a greater effect on flow than placing it in front of the ridge does, suggesting that ridges have a greater effect on flow rates. The flow rate can be controlled precisely by adjusting the phase angle and phase difference in the rough channel. When the ridge height is comparable to the electric double layer thickness, there is a large variation in flow rate. The flow rate of a fluid passing over a taller, highly charged obstacle is reduced.
Our results show the importance of surface properties to flow rates in a microchannel and demonstrate the advantage of the lattice Poisson-Boltzmann method with a periodic driving force. We propose a simple computational scheme and driving way for simulating electro-osmotic flows in microchannels with complex geometries.

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