近年來，微機電系統與製程技術已成功將生醫和化學分析系統微小化，並進一步實現微型全分析系統的夢想。為了達到全自動化的目的，流體樣本的驅動與控制是成功的關鍵。本論文中我們提出了一種新穎的被動式流體驅動與控制方法，不需外加動力即可達到樣本流體驅動與時序控制的目的，並據此開發一個可攜式的微流體驅動與自動控制晶片，使用上只需滴水即可啟動系統。本系統由三層高分子結構所組成，最上與最下分別為控制流道與樣本流道層，並在其中加入一層薄膜做為控制流體推動樣本流體的介質，以壓擠的方式驅動並控制樣本在流道中的運動。基本上我們是以滲透作用做為驅動控制流體的動力源，因此具備等流速與高驅動壓力等優點，控制流體的流動會擠壓隔膜，取代活塞等傳統機制以驅動下層的樣本流體，同時搭配壓感開關(pressure sensitive switch)與驅動延遲流道(time delay channel)的作用，並整合單向閥門，順利實現具有樣本自動充填，以及停滯和流速自動切換等功能的被動式微流體驅動與控制晶片。其中我們可依不同的幾何空間配置與半透膜透水面積，有效控制樣本輸出流速與停滯時間等參數。依目前的設計以10.5 mm2 的滲透面積可使樣本流體以0.095 mm3/s的流速流動約30秒後，接著停滯約220秒，最後再以0.095 mm3/s的流速作用約20秒的時間，並可進一步調整各項參數。此一方法可有效擴充，控制多個開關與閥門的作用以創造出複雜且多樣化的功能，未來將可望應用於可攜式檢測系統，自動完成一系列的定量與定時檢測動作，簡化生醫與化學檢測流程並有效降低其成本，實現多功能微型全分析系統的目標。

In the past few years, micro-electro-mechanical-systems (MEMS) technology and micromachining techniques have enabled the miniaturization of biomedical and chemical analysis devices and systems. Furthermore, technologies for realization of microfluidic systems have been demonstrated since the advent of micro-total-analysis-system (u-Tas).The micropump is the most important device for purpose of the automation in the microfluid system. In this article, we present a novel passive fluid-driven control method, without external power and can achieve the purpose of the sample fluid drive and timing control. In this way, it can be developed a portable microfluidic-driven and automatic control chip, The user only needs to drop a few water to start this system. The system is generally divided into three PDMS layers, the top and bottom are control channel and fluid channel, respectively, and the middle of two layers are added a layer of PDMS membrane as a medium for the promotion of the sample fluid, and we can drive and control sample fluid by deforming the PDMS membrane. Basically, we use osmosis as the power source of the driving and controlling the fluid, hence, it have the advantages of constant flow rate and high driving pressure. The flow of control fluid will squeeze the membrane, replace the piston and the traditional mechanisms of fluid driving to drive the lower sample fluid. We also design a series of pressure sensitive switch, time delay channel , check valve integrated and negative pressure source to successfully achieve the passive microfluidic drive and control chip with automatic filling of the sample, as well as stagnation and flow rate automatically switching, which according to our geometric space configuration with semi-permeable membrane permeable area to effectively control the parameters of the sample output flow rate and delay time. Followed by our experimental setup, we can drive the sample output with 0.095mm3/s in about 30 second and stop it in about 220 second, and finally drive it with the same flow rate in about 20 second once again. This method can be effectively expanded to control the role of multiple switches and valves to create a complex and diverse functions, portable detection system is expected to be applied automatically to complete a series of quantitative and timing detection action, simplify raw medical and chemical detection processes and reduce costs to achieve the goal of micro-total-analysis-system.

[1] Steigert, J., et al., “Integrated Sample Preparation, Reaction, and Detection on a High-frequency Centrifugal Microfluidic Platform”. Journal of the Association for Laboratory Automation, 10(5): pp. 331-341, 2005.
[2] Zengerle, R. and T. Metz, “Capillary Driven Systems”, in Microfluidic Platforms. p. 42, 2006.
[3] S. Shoji, S. Nakagawa and M. Esashi, “Micropump and sample-injector for integrated chemical analyzing systems”, Sensors and Actuators A, Vol. 21-23, pp. 189-192, 1990.
[5] R. Zengerle, A. Richter, and H. Sandmaier, “A micro membrane pump with electrostatic actuation,” in Proceeding IEEE Micro Electro Mechanical Systems, (Travemunde, Germany), pp. 19-24, 1992.
[6] R. Rapp, W. K. Schomburg, D. Maas, J. Schulz and W. Stark, “LIGA Micropump for Gases and Liquids,” Sensors and Actuators A, Vol. 40, pp. 57-61, 1994.
[7] T. S. J. Lammerink, M. Elwenspoek and J. H. J. Fluitman, “Integrated micro-liquid dosing System”, in: Proceedings of the IEEE Micro Electro Mechanical Systems, Fort Lauderdale, U.S.A., pp. 254-259, 1993.
[8] Jang J., and Lee S. S., “ Theoretical and Experimental Study of MHD (magnetohydrodynamic) Micropump,” Sensors and Actuators A, v 80, pp. 84-89 , 2000.
[9] Ahn S. and Kim Y., “Fabrication and experiment of a lanner micro ion drag pump”, Sensors and Actuators, A70,pp. 1-5, 1998.
[10] M. Khoo and C. Liu, “A Novel Micromachined Magnetic Membrane Microfluid Pump,”
Proceedings of the 22nd Annual International Conference of the IEEE, Vol. 3, pp. 2394-2397, 2000.
[11] Juncker, D.; Schmid, H.; Drechsler, U.; Wolf, H.; Wolf, M.; Michel, B.; de Rooij, N.;Delamarche, E. “Autonomous microfluidic capillary system”. Anal. Chem., 74, pp. 6139-6144, 2002.
[12] Berthier, E.; Beebe, D.J.” Flow rate analysis of a surface tension driven passive micropump”. Lab Chip, 7, pp. 1475-1478, 2007.
[13] Iwai K.; Sochol R. D.; Lin L. “FINGER-POWERED, PRESSURE-DRIVEN MICROFLUIDIC PUMP”. IEEE MICRO ELECTRO MECHANICAL SYSTEMS pp.1131-1134, 2010.
[14] Terry, S.C.; Jerman, J.H.; Angell, J.B. “Electron Devices”. IEEE Transactions, Vol.26 pp. 1880-1886, 1979.
[15] Oh, K.W. and C.H. Ahn,” A review of microvalves”. Journal of Micromechanics and Microengineering. 16(5), pp. R13-R39 , 2006.
[16] Bae, B., et al., “Feasibility test of an electromagnetically driven valve actuator for glaucoma treatment”. Microelectromechanical Systems, Journal of 11(4): pp. 344-354, 2002.
[17] Teymoori, M.M. and E. Abbaspour-Sani,” Design and simulation of a novel electrostatic peristaltic micromachined pump for drug delivery applications”. Sensors and Actuators A: Physical. 117(2): pp. 222-229, 2005.
[18] Li, H.Q., et al., “Fabrication of a high frequency piezoelectric microvalve”. Sensors and Actuators A: Physical. 111(1): pp. 51-56, 2004.
[19] D. T. C. Noo Li Jeon, Christopher J. Wargo, Hongkai Wu, Insung S. Choi, Janelle R. Anderson and George M. Whitesides, “Microfluidics Section: Design and Fabrication of Integrated Passive Valves and Pumps for Flexible Polymer 3-Dimensional Microfluidic Systems" Biomedical Microdevices, vol. Vol 4, 2002.
[20] Weibel, D. B., Kruithof, M., Potenta, S., Sia, S. K., Lee, A. and Whitesides, G. M., “Torque-actuated valves for microfluidics”, Anal. Chem., (77), p. 4726-4733, 2005.