近年來光學偵測方式被廣泛地使用在微流體生物晶片上並應用於生物或是化學檢測。本研究使用微機電製程技術製作光流體晶片，其主要的功用分為兩大部分：(1)用於測量液體的折射率及濃度 (2)用於檢測尿比重。
利用影像分析的技術，希望可以製作出不需要雷射儀器、CCD攝影機、示波器等較昂貴的實驗儀器，只需要單眼相機與電腦分析軟體，就可以測量液體的折射率及檢測尿比重。
本研究中的光流體晶片是利用影像分析的方法來量測，我們在晶片中設計一條50μm寬的直線圖案，通入不同折射率的待測液體至量測腔體中，透過待測液體去觀察直線圖案，由於折射率的不同，直線圖案會產生位置上的偏移，以空氣為基準，可以得到不同折射率的偏移距離，我們便可以利用此偏移距離的特性，來做折射率、濃度的量測與尿比重的檢測。
在量測液體的折射率及濃度的部分，我們選用了氯化鈉、氯化鈣、氯化鋰，這3種化學物質，調製出不同濃度跟折射率，利用本研究的光流體晶片以影像分析的方法來做量測。在檢測尿比重的部分，我們檢測測試者的尿液來做檢測。因為尿液中葡萄糖的濃度是影響尿比重正常與否的最大因素，所以利用飽和濃度的葡萄糖水加入檢體中確認葡萄糖與尿比重的關係。
利用影像分析來做檢測的技術，可以運用在許多光流體檢測元件上，相較於傳統的光學元件，減少使用了昂貴儀器的使用，而且也改善折射率量測範圍上的限制。

Recently, optical methods have been widely used for biological and chemical detection in microfluidics or lab-on-a-chip systems. In this research, we use MEMS technology to fabricate the optofluidic chip. There are two major functions in this device: (1) the measurement of refractive index and concentration and (2) the detection of urine specific gravity.
By using image analysis, we design an optofluidic device to measure refractive index, concentration and urine specific gravity without expensive instruments such as laser device, CCD camera, and oscilloscope. We only use camera and computer analysis software to complete the research.
In this study, we design a line pattern which is 50μm wide and observe this pattern through the refractive index of different analytes. According to difference of refractive index, the position of line pattern which we observed will change. We set the position of air as a standard position. Then, we define the difference of position between air and analytes as departure distance. We can use departure distance to identify the refractive index or urine specific gravity of analytes.
For refractive index measurement, we select three chemical solutions of NaCl, LiCl and CaCl2 that have different concentrations to demonstrate the proposed optofluidic device. For urine specific gravity measurement, we detect urine of testers to measure the urine specific gravity. Due to the glucose is the major factor which increases the urine specific gravity, we mix saturated solution of glucose into urine of tester to verify the relationship between the glucose and the urine specific gravity.
Compare to traditional optic device, image analysis technology reduced the cost of expensive instrument and improved the limit of refractive index measuring range. The image analysis technology can be applied to optofluidic measurement on a chip by a simple, fast and user-friendly.

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