自工業革命以來，越來越多的汙染物隨著科技的發展被釋放到地球上來，水汙染是全球性的問題，在眾多水汙染中對人體最嚴重的就屬重金屬離子了。縱使人類從環境或魚類中接觸到重金屬是非常微量的，然而經年累月長時間接觸下來，也會因為重金屬在人體中有累積性而損害人體，因此檢測重金屬一直是一個被重視的課題。
由於檢驗重金屬在傳統的儀器需要專業的人員以及大量的耗材，例如X射線螢光光譜（X-ray Fluorescence Spectrometer, XRF）、電感耦合等離子體質譜（Inductively Coupled Plasma Mass Spectrometry, ICP-MS）等等，這些專業的儀器通常價格昂貴或是不是每實驗室都有，如需使用必須借用或者是租用。而微流道由於其體積小、消耗試劑少、方便、以及操作容易為研究所歡迎。而除了檢測重金屬之外，微流體晶片在其他生物醫學檢測例如檢測血液、蛋白質中也有很好的發展。
本實驗為了證明適體與金屬離子能完全混合，使用一個被動式的微流道系統，其微流道設計兩入口寬度0.6 mm、高度0.15 mm、長度10 mm，流道截面寬度為0.6 mm、高度0.15 mm，流道體積扣掉入口流道為總混合體積為7.34 mm3。實驗結果並與COMSOL Multiphysics模擬結果進行比較，由於本實驗觀察的顏色為整體流道深度之垂直平均，固在模擬結果也必須依照相同條件，把整個流道深度的結果統整在流道表面。最後實驗與數據模擬兩者的結果高度的相符，在出口端最高的誤差都在3%以下，驗證了此晶片可以達到良好的混合效果。

關鍵字: 微流道、液體混合、檢驗重金屬、汞離子、鉛離子

Water pollution seriously affects human health. Detection of water quality is thus important to human survival. Human exposure to heavy metal ions from the environment is inevitable. However, heavy metals can accumulate in the human body and harm it. Thus, detecting heavy metal ions in water is one of the major targets for improving the environment. Different from traditional instruments requiring professional machines such as X-ray fluorescence spectrometers (XRFs) or inductively coupled plasma mass spectrometers (ICP-MSs), etc., microfluidic devices, which are fast and convenient and have low sample requirements and good sensitivity, can be used for this purpose. They reduce costs and also reduce the need for reaction reagents.
In this study, our team designed a mixing microfluidic channel and used it to perform mixing experiments. The numerical simulation and the mixing experiment were used to calculate the mixing index of the microfluidic channel, and the simulation and experimental results obtained using COMSOL software showed that the mixing index was higher than 90% at flow rates of 1 (μl/min), 3 (μl/min), and 5 (μl/min) and higher than 85% at flow rates of 8 (μl/min), and 10 (μl/min). The mixing index was higher than 85% at a flow rate of 8 (μl/min) and higher than 77% at a flow rate of 10 (μl/min). In addition, the simulated mixing index was in good agreement with the experimental results, where the average difference for each flow rate was less than 5%.

Keywords: Microchannel, Mixing Index, Detection of heavy metals, Fluid mixing

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