微流體晶片之新型注射系統模擬分析

Numerical Analysis of Injection System in Microfluidic Chip

王柏彬(Bai-Bin Wang)

指導教授 ： 傅龍明

國立屏東科技大學/工學院/材料工程所/碩士(2007年)

https://doi.org/10.6346/NPUST.2007.00060

摘要

在這篇文章裡是利用數值模擬的方式來分析，而且還對一些微流體相關的公式進行說明，並針對不同幾何形狀的微管道來做模擬，進而去了解管道中流體的各種物理性質，在這裡就十字型微管道，雙T 型微管道，以及90度與45度U型微管道進行模擬分析，研究管道中的電場分布和電雙層分布，以及管道中注射與分離的濃度分布的情形，而所做的濃度模擬圖裡面的壓力設定更是困難，只要設定有偏差作出來的濃度模擬圖的會誤差相當大，會影響分離的結果，所以在模擬中要不斷試到可以為止，這是相當耗費時間的。此外，也可以從不同漸擴管長度之下的濃度圖可以看出，隨著管徑比例越大相對的液體流過時，濃度會被平均的分配，來改善檢測液帶寬分布，而就不同管徑比例和漸擴管的長度來觀察其濃度變化，由大到小可以很明顯的看出，在出口端濃度的輪廓會由半月型逐漸轉為越來越平坦，這是因為在管徑比例較小而漸擴管長度比較短的出口端的速度梯度的變化大所以才呈現半月型，而在管徑比例較長和漸擴管長度增加之下的出口端的速度梯度的變化小，所以才呈現比較平坦的現象，所以相對的檢測液濃度的帶寬也會得到改善，並增加分離的效果。

關鍵字

數值模擬 ； 注射 ； 分離 ； 微流體

並列摘要

This study develops a novel capillary electrophoresis (CE) microfluidic device featuring a conventional injection system (including cross-form, double-T-form, and U-form injection system) and an expansion chamber located at the inlet of the separation channel. The combined injection system / expansion chamber arrangement is designed to deliver a high-quality sample band into the separation channel such that the detection performance of the device is enhanced. Numerical simulations are performed to investigate the electrokinetic transport processes in the microfluidic device and to establish the optimal configuration of the expansion chamber. The results indicate that an expansion chamber with an expansion ratio of 2.5 and an expansion length of 500 micrometer delivers a sample plug with the correct shape and orientation. With this particular configuration, the peak intensities of the sample are sharp and clearly distinguishable in the detection region of the separation channel. Therefore, this configuration is well suited for capillary electrophoresis applications which require a highly sensitive resolution of the sample plug. The novel capillary electrophoresis microfluidic device developed in this study has an exciting potential for use in high-performance, high-throughput chemical analysis applications and in many other applications throughout the field of micro-total-analysis-systems.

並列關鍵字

numerical simulation ； injection ； separation ； microfluidic body

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