以螢光微膠囊與低溫顯微鏡探討螢光影像之溫度效應

Abstract

溫度的量測一直是被重視的問題，近代甚至發展出以光學原理檢測溫度之技術，螢光測溫技術即為其中之一分支。利用螢光來量測溫度可以克服過去被量測物處於高電壓、高磁場環境下，一般溫度感測器無法順利量測到之情形。本研究應用螢光影像之方法來量測溫度，主要先藉由熱電致冷式低溫顯微鏡來模擬環境溫度，並利用低溫顯微鏡可即時控制溫度之功能，達到快速且即時模擬溫度之需求。研究中使用內含螢光溶液之微膠囊做為實驗樣本，並對其進行激發，然後觀察其在不同溫度下之螢光影像強度。實驗內容主要分成兩大部份，第一部份為分別對不同環境變因進行螢光微膠囊的實驗，以探討螢光在不同濃度與溶劑之激發情形，並進行不同螢光微膠囊大小與激發光源距離的螢光實驗，最後利用這些數據找出適合後續實驗之條件。第二部份則是對螢光影像強度進行溫度的量測，方法是利用所獲得之螢光影像經分析後建立的螢光量測模型，以此模型對螢光微膠囊所在之環境溫度進行量測，可量測溫度範圍為介於-15~ 90 ℃之間。本研究建立之螢光量測模型所使用之方法包含螢光隨時間衰減法、單一螢光強度法及螢光比值法，其均方根誤差分別為9.74 ℃、5.04 ℃及3.41 ℃；且在三次不同實驗中所得之迴歸判定係數分別為0.890、0.979及0.992。實驗結果顯示，利用螢光微膠囊所獲得之螢光影像在不同環境溫度下其強度有不同之變化，因此可應用於溫度的量測；而所建立的螢光量測模型中，使用螢光比值法有較佳的結果，實驗的重複性也較其他方法來得好。

Measuring temperature is a very important issue. Recently, using optical technologies to measure temperature has been developed, such as fluorescent imaging. This method can overcome the problem that objects under the situation of high voltage or high magnetic field, which normal thermometer can’t apply. In this research we using fluorescent imaging technology to measure temperature. The main idea is using thermoelectric cooler cryomicroscope which can control temperature easily to simulates temperature we needed. The samples in this research are fluorescent microcapsules, then excited it by blue LED and observed intensity of fluorescent image in different temperature. This research can be divided into two parts. The first part is to investigate the effect of different conditions to fluorescent microcapsules, such as size of microcapsules, distance of excited light, concentration of fluorescent solution. The second part is to establish measurement models by experimental results, then using the models to measure the temperature. The measurable range is -15 ~ 90 ℃. The models in this research are based on method of fluorescent decay, method of single fluorescent intensity, and method of fluorescent ratio. Each method has best RMSE = 9.74 ℃, 5.04 ℃, and 3.41 ℃. And R2 = 0.890, 0.979, and 0.972. The results show fluorescent imaging technology can really apply to temperature measurement, also the best model is method of fluorescent ratio, and it more repeatable than other methods.