電化學氣泡式微型幫浦於純血輸送之研究

An Air-Bubble-Actuated Electrochemical Micropump for On-Chip Blood Transportaton

邱聖弘(Sheng-Hung Chiu)

指導教授 ： 劉承賢

國立清華大學/工學院/奈米工程與微系統研究所/碩士(2008年)

摘要

整合機、電、生、化的血液檢測型微流體系統晶片，在臨床診斷、醫療檢測上愈發扮演重要的角色，藉由血液的檢測，可以得知許多身體的健康訊息。微幫浦是此類微流體晶片上極具挑戰的研發重點，其發展以及應用，國際間正朝向一種能達到低耗能、低驅動電壓以及室溫操作來發展，以避免對檢測的血液內細胞產生影響。電解氣泡方式是最為符合以上三要件之致動器，但傳統電解氣泡式微幫浦受限於流道中的液體，電解造成液體pH值生化特性的改變以及流道阻塞(chocking & sticking)的現象，大多不能用在血液傳輸上。本研究發展出一種新型電解氣泡致動式微流體幫浦，藉由流道形狀與鐵弗龍(Teflon)疏水區塊的設計形成一個特殊之隔離來創造一種新的幫浦機制，使電解液與欲推動液體分隔開來，適合用在微流體晶片的血液傳輸上。再加上對氣泡產生的時序控制，可以達到連續輸送微流體的目的。我們還對流道表面作改質，以防止因為血小板凝結造成的阻塞(clotting)。經由我們的實驗結果，顯示此一裝置不但製程簡單且可有效的輸送流體前進。且藉由在不同施加電壓下，量測氣泡膨脹時間以及氣泡排除時間以計算所需的連續控制信號操作頻率，以利於精確控制流體流速。
本研究中，我們成功的發展了一種新式的電化學微型幫浦，其關鍵特色是低耗能且不影響待驅動流體的pH值等生化特性。此幫浦運作時，無須高溫、高電壓、強磁場等操作條件，而以空氣氣泡間接致動輸送血液，相較於其他致動機制，其非破壞性的優點，尤適用在生物體的輸送。pH值及血小板黏附測試、設計概念、理論推導、微製程、以及性能量測全都詳細敍述於本文各章節中。以未來應用端來看，特別適合可攜式(portable)及植入式(implantable)的低耗能生醫晶片。

關鍵字

微型幫浦 ； 電解 ； 空氣氣泡 ； 表面改質

並列摘要

A novel electrolysis-based micropump using air bubble to achieve indirect actuation is proposed and successfully demonstrated. Unlike most other electrochemical micropumps, our micropump could drive microfluid without the pH-value variation and the choking/sticking phenomena of electrolytic bubbles in the main channel. Besides, the room temperature operation and the low driving voltage used for the electrolysis actuation minimize the possibility of cell-damage. It is promising for biomedical applications, especially for the blood transportation. The whole blood is an intrinsically complex material and difficult to be manipulated in the microdevices. Moreover, the on-chip electrolysis-bubble actuator with the features of large actuation force, low voltage and low power consumption enable portable and implantable lab-on-a-chip microsystems. Utilizing the hydrophobic trapeziform pattern located at the junction of the T-shaped microchannel, the micropump drives the pumped fluid in the main channel and isolates it from the electrolytic bubbles. Our proposed micropump can be used for a variety of applications without constraints on the pumped liquid. Polyethylene glycol (PEG) is employed to modify the surface of PDMS microchannel to prevent the platelet adhesion during pumping operation. According to the platelet adhesion test, there is no clotting during blood pumping operation. The pH-value variation and distribution in the side channel and the main channel is also characterized during electrolysis-actuation operation. Experimental results show that the liquid displacement and the pumping rate could be easily and accurately controlled via the signal of two-phase peristaltic sequence and the periodic generation of electrolytic bubbles. With the applied voltage of 2.5 volts, the maximum pumping rate of 121 nl/min and 88 nl/min were achieved for the DI water and the whole blood, respectively, with the microchannel cross section of 100×50 μm. In this thesis, the design, microfabrication process, characterization and the experimental demonstration of this novel micropump are reported.

並列關鍵字

micropump ； electrolysis ； air bubble ； surface modification

參考文獻

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