圓形真空模組開發與動態特性分析以及其應用於微流體晶片兩段式精準傳輸

Development and Dynamic Characterizations of Circular-Type Vacuum Modules and Their Applications to On-Chip Two-Stage Precise Microfluidic Delivery

鍾文(Chung, Wen)

指導教授 ： 洪健中

國立清華大學/工學院/動力機械工程學系/碩士(2013年)

摘要

過去研究文獻發展了許多微流體驅動元件，但大多於實際應用時都有其限制以及缺點，包含體積龐大、需要額外管線連接、無法達到多段式操作、需要預先置入液體於晶片內、難以達到精準控制以及無法直接用於生醫晶片上之操控等瓶頸。在本論文研究中，以形狀記憶高分子發展之微小化真空模組，配合重新製作之圓形模具，達到體積微小化、極易脫膜、價格低廉、可大量製作以及重複製作等商業化需求，並且利用簡易方式貼合於生醫晶片上，配合已開發之PID (proportional-integral-derivative controller) 溫控加熱系統達到兩段操控、程式化之穩定加熱驅動、精準操控等等需求。本研究有效的改善前述微流體幫浦元件之限制，且利用程式化之方式達成穩定之加熱驅動，並且對於加熱時熱干擾、長時間存放、動態變形量等過去未探討之部分都已詳細探討並改善，藉此更進一步的發展更完善之微流體操控系統。
本研究主要分為三部分，其一為對於過去發展真空模組進一步的分析改善，吸放熱測試中之變異達 3.69% 與 5.33% 。同時由過去之方型改善為圓型，藉此可減少 22.6% 之材料消耗，並且有更佳之變形容忍量，而且在更進一步的微小化圓型之真空模組，相較過去方型之面積縮小至 44.18% ，經網格分析後顯示此微小化後之圓型真空模組之變形移動量相較於同尺寸之方型真空模組減少 33.65% 。
其二為對於真空模組之加熱變化動態型為探討，利用已開發完成之PID溫控加熱源，探討於定溫定時加熱下其厚度變化之狀況，以60°C加熱20秒開始變形回復。在長時間存放實驗中，最佳之存放條件為放置於冰箱內保存，於246 天內僅回復1%左右，相對於存放於有空調之室內約為 6.7% 。
其三為實際應用於生醫晶片上之狀況，此處我們探討了三個不同加熱溫度下之回復狀況，得知高溫時的確會使加熱速度上升，但會影響晶片流道內之溫度，此處我們以紅外線攝影得知熱分布狀況，並且分析後得到使用兩段式加熱方式，分別為設定 100°C 加熱40秒後改為 80°C 再加熱 40秒 ，會有最佳之回復狀況，同時對於晶片內流體樣本之干擾最小，並且量測晶片內產生之動態負壓，兩段式驅動時第一段約為 -0.3 psi，而第二段約為 -0.7 psi，以及單一一個真空模組產生之負壓，約為-1.5 psi ~ -2 psi，後續利用此參數輸入至程式化加熱，以此方式探討多片晶片之流體驅動狀況，並且達成兩段式的精準微流體驅動。

關鍵字

形狀記憶高分子 ； 微幫浦 ； 實驗室晶片 ； 微流體

並列摘要

In the past research, lots of micropump devices were developed. However, most of them have its limit in actual applications, including large size, external tubing required, cannot achieve multi-stage manipulation, liquid preloading required, hard to achieve precise control, bad on-chip capability etc. In this thesis, the developed miniaturized vacuum module made of shape memory polymer, with our new mold, successfully achieve commercialized requirement like small size, easy demolding, low price, and be able to mass production. By easy-attaching process, and developed fully-integrated PID (proportional-integral-derivative) temperature control heating system, the vacuum modules also achieve two-stage, programmed heating system, and precise control. This research successfully improves the cons of previous micropump devices, and also has a deeper investigation in heat interference, long-term storage, and dynamic transformation of the developed vacuum module.
This research could be divided into three parts. In the first part, we have a further investigation in the past vacuum module. In the exothermic and endothermic experiment the (C.V) Coefficient of Variation value between three batches of vacuum module are 3.69% and 5.33%. And by changing the shape from square to circular, the material consumption can be reduced by 22.6% and with a better transformation tolerance. And we further miniaturized the vacuum module, reducing the cross-section area to 44.18%, compared to past vacuum module. After the grid analysis, the moving point transformation ratio is 0% in circular shape and 33.65% in square shape.
In the second part, we investigated the dynamic transformation of the developed vacuum module. With the developed PID temperature control heating system, we use laser displacement instrument to examine the thickness change in constant temperature heating. We got the conclusion that we need at least 20 second to actual trigger the transformation in thickness of vacuum module. And also in the repeating heating experiment, we need more heating interval than previous one to get further thickness change. In the long-term storage experiment, the best storage condition was in the refrigerator - only 1% change in 246 days was measured. In other hand, 6.7% change in the room with air-conditioner was still acceptable.
In the third part, we investigate the condition in chip application. Here we test three different heating temperatures, and knowing in higher heating temperature, the transformation did speed up. However, this causes great effect in the temperature inside the chip microchannel. And by the IR photography analysis, we change our heating program to 2-Step heating, setting 100°C for the first 40 second and 80°C for the continuous 40 second, which has the best balance between transformation speed and temperature in the microchannel. Also the generated back pressure was also investigated. In single vacuum module, -1.5 psi ~ -2 psi was measured, and in the actual on-chip multi-stage experiment, -0.3 psi was measured in first stage, and -0.7 psi was measured in second stage. Furthermore, six actual chips were tested and successfully achieved two-stage precise microfluidic delivery.

並列關鍵字

Shape Memory Polymer ； Micropump ； Lab-on-a-chip ； Microfluidic

參考文獻

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