應用於微流體晶片之可撓性薄膜致動器

A PDMS thin membrane actuator for micro-fluidics application

吳景揚(Chin-Yang Wu)

指導教授 ： 劉承賢

國立清華大學/工學院/動力機械工程學系/碩士(2009年)

摘要

在實驗室晶片的發展上，細胞的操控是一個重要的議題，如何對細胞進行準確地引導、定位悠關生物實驗的成敗。而使用的技術更是關鍵，不良的技術容易導致細胞受損而使得其原本具有的功能喪失，甚至死亡。目前在已有的技術中，常被應用的是微流體電動力學(electrodynamics)中的介電泳、電滲流、光鑷夾(Optical Tweezers)、磁力操控、微型鑷夾…等並搭配微流道的設計與微流道元件的使用，如微幫浦、微型閥…等來達成目標。然而，這些操控技術各自存在著一些限制與缺點，例如所使用的溶液易造成細胞的傷害或過多的外界能量與接觸而造成細胞的缺損。
在參考了C.J.Kim教授團隊的微型籠設計與我們實驗室先前所發展的仿龍蝦觸鬚式的致動器的設計後，加入以薄膜形變使其上結構物能產生側向致動的想法，我們希望能發展一種能應用在各式操作流體，突破上述微流體電動力學的限制，以期能在真實的細胞培養液、血液等環境操控細胞。致動的動力來源來自針筒式幫浦，利用其穩定的操作與控制，能使我們的薄膜致動器具大位移，大出力優點。
本論文的研究中，完成了以簡易的模型預測可行性、以模擬軟體ANSYS對薄膜受壓力形變的模擬、實驗用晶片的設計、晶片製作的開發、晶片可靠度的測試、致動器特性的量測，與一個在微流道內對生物細胞團進行捕捉與釋放的實驗。

關鍵字

微機電 ； 微流體 ； 薄膜形變 ； 致動器 ； 生物細胞團

並列摘要

In the development of the lab chip, cell manipulation is always an important issue. How to guide or position cell accurately would determine whether the experiment result is good or not. Besides, the technique chosen is almost critical. The inappropriate technique would damage the cells easily, and result in either degradation of cell function, or even cell death. In the techniques developed nowadays, involved with microfluidic channel and microfluidic components, researchers often adopt electrodynamics method, either dielectrophoresis or electroosmosis, optical tweezers, magnetic manipulation, microgrippers to achieve the goal of cell manipulation. However, these techniques have inherent drawbacks. For example, the buffer needed in dieletrophoresis and electroosmosis is usually not suitable for cell viability. Also the power of optical tweezers might result in some damage on cell.
Based on the idea of microcage and the design of Lobster-sniffing inspired biomimic actuator developed by our lab, we introduce the idea of putting a small structure on a PDMS thin membrane with some offset to approach similar functions. While the PDMS thin membrane is actuated by the syringe pump, the small structure could provide a lateral actuation. Compared with the microfluidic electrodynamics, such an actuation method would have no constraint on the working fluid. The experiments show that it could function well in the cell culture solution, and even blood fluid. Also, benefited from the syringe pumps, such an actuation would provide large actuation rage and large force in the microchannel.
At this stage, an easy calculation for membrane deformation model, ANSYS simulation for membrane deformation, device design, chip development, and the measurement for the characteristics of the chip have been finished. Also, an experiment for the trap and release of spheroids in culture medium has been demonstrated preliminarily, showing the practice of our PDMS membrane actuator.

並列關鍵字

MEMS ； microfluidics ； membrane-deformation ； actuator ； spheroid

參考文獻

[1] Long-Sheng Fan, Yu-Chong Tai, and Richard S. Muller, “IC-Processed Electrostatic Micro-motors,” Electron Devices Meeting, IEDM '88. Technical Digest.

[2] Helene Andersson, Albert van den Berg, “Microfluidic devices for cellomics: a review” Sensors and Actuators B 92, 315–325 (2003).

[3] C. Chang, C.-F. Chiang, C.-H. Liu,C.-H Liu, “A Lobster-Sniffing-Inspired Method for Micro-Objects Manipulation Using Electrostatic Micro-Actuators,”Journal of Micromechnanics and Microengineering, 15 812-21 (2005).

[4] Joel Voldman, Martha L. Gray, Mehmet Toner, and Martin A. Schmidt, “A Microfabrication-Based Dynamic Array cytometer,” Anal. Chem., 74 3984-3990 (2002)

[5] A. Ramos, A. Gonzalez, A. Castellanos, N. G. Green, and H. Morgan,Phys, “Pumping of liquids with ac voltages applied to asymmetric pairs of microelectrodes,” Rev. E 67, 056302 (2003).