生物感測技術作為分子檢測的平台，提供了生物樣品中的內含物種類，或者已知樣品的濃度測定等相關訊息，在疾病檢測與生醫研究扮演重要角色。在生物樣品檢測實驗當中，待測生物樣品的濃度依據生物體的表現量有所不同，時有樣品濃度過低，無法突破儀器靈敏度極限，導致儀器無法偵測樣品的存在。解決樣品的濃度過低問題，一般性的策略是使用濃縮技術，使待測樣品濃度增加以符合檢測需要。然而，泛用的濃縮技術，如高速離心，對於分子尺寸較小的待測物，需要長時間的離心才有辦法達成濃縮目的，而延遲整體實驗進程，甚至提高生物樣品質變的風險。因此，高效率的濃縮技術，對於生物檢測進程的效率提升有研究的必要。

由於近年微流道系統的發展製作各種生物晶片，使我們得以在小尺寸的生物晶片上完成複雜實驗，是生物檢測的重要發展方向。因此，本文的研究著重於在微流道晶片當中製作元件，有效率的濃縮小分子輔助生物檢測的進程。在實驗的設計上，我們在微流道晶片結構中，製作奈米流道搭配電場的施加，透過電雙層的效應達成有效率的分子濃縮。在製程上我們首先以聚焦離子束(Focused Ion Beam, FIB)，在SU-8模組上加工出奈米線；接著透過黃光微影製SU-8光阻組成的微流道模具，搭配軟式微影製程以PDMS (polydimethylsiloxane )完成微流道晶片製作。由相關文獻中顯示，微流道的幾何結構，會影響分子收集效率的情形。因此，我們的研究重點在於改變微流道寬度結構，探討微流道的幾何結構對收集分子效率的影響。在微流道的幾何設計上，我們對微流道的局部結構，改變微流道寬度(30μm, 20μm, 10μm)，觀測局部流道寬度改變後，對分子收集的影響。

整體研究結果共分為模擬與實驗兩部分，在模擬方面是使用有限元素分析(Finite Element Method, FEM)藉由改變電位的方式來探討不同微流體尺寸寬度與不同奈米流道尺寸之微流體裝置電場與電滲透流差異。在實驗方面，我們先觀測不同尺寸之微米流道寬度與奈米流道對於螢光分子之收集結果。實驗的結果顯示，寬度20μm微流體裝置螢光粒子的收集效率最高，另外當奈米流道尺寸越小時，會使螢光分子的收集效率更加提升。第二部份我們討論元件使用的過程中產生的奈米流道堵塞時，對電雙層強度之影響，用以提供未來元件改善建議。第二部分的實驗結果呈現，當奈米流道堵塞越大時電雙層效果越明顯且集中效果越佳。

The bio-sensing technology can be acted as an important role of molecular detection platform in disease detection and biomedical research, which not only provides details for bio-sample, but the information of sample concentration. In the experiment of sample detection, the concentration of the sample which should be tested will vary large differences; thus reaches the sensitivity of the apparatus, leading to the disable-detection of the presence of the sample. To manage the problem of low concentration, the common strategy is using inspissation technology, fitting the needs of the detection. However, the above technology, for example, high-speed centrifugation, for small samples, should take longer times and higher the risk of metamorphism. Thus, high efficiency of the inspissation technology should be necessarily researched.

Due to the system of nanochannel, it helps make many kinds of bio-chips; thus helping us to do the complete experiment for bio-sample. Therefore, our research is aimed at making components for bio-chips, making high efficiency progress at bio-detection for concentrating molecules. For the design of this experiment, we additionally fabricate nanochannel with electric field through electric double layer effect to accomplish the effective inspissation of molecules. And for the fabrication part, we first use Focused Ion Beam, FIB, to make nanowires at the mold of SU-8; then we use soft-lithography with Polydimethylsiloxane, PDMS, to finish our microchannles. Based on the references, they indicated that the geometry of the microchannel will affect the molecular-collection of the efficiency. So, our research also aim at changing the width of the microchannel. For our geometry, we design the width of 30μm, 20μm and 10μm respectively, investigating the changing of the width and see what’s affecting our collection-efficiency.

The whole research can be distinguished into two parts, simulation and experiment. The simulation is to use the approach of Finite Element Method, FEM, to change the potential, discussing different kinds of nanochannel-width, microfluidic electric field and electro-osmotic flow. And for the experiment part, we observe the results of the collection of fluorescent molecules in different microchannel-width first. The experiment result indicates that 20μm width of microchannel has the highest collection-efficiency. Besides, when changing dimensions smaller, the collection-efficiency will enhance. The second part we discuss while happening blockage of the nanochannel when used, what will be affected for the electric double layer. The second part shows that while severely blocked the nanochannel, the effect of the electric double layer will be more obvious and finely-collect.

摘要 Ⅰ
目錄 Ⅴ
圖表目錄 Ⅶ
符號說明 Ⅹ
第一章、緒論 1
1.1前言 1
1.2研究動機與目的 2
第二章、基本原理與文獻回顧 5
2.1電動流效應 5
2.2 電雙層形成機制 6
2.3電滲透流形成機制 8
2.4電泳效應 9
2.5濃度極化現象 12
2.6稀薄濃度生化樣品集中之相關文獻 14
第三章、研究方法 25
3.1設計概念 25
3.2模擬簡介 26
3.2.1統御方程式 ...26
3.2.2流體特性設定 ...28
3.2.3流體邊界條件設定 ...29
3.3 微流體元件製作 ...31
3.3.1 第一道黃光微影製程 ...32
3.3.2 聚焦離子束加工 ...34
3.3.3第二道黃光微影製程 39
3.3.4PDMS翻模與氧電漿接合 41
3.4 實驗配置 ...42
3.4.1實驗裝置與樣品前置準備 ...43
3.4.2收集操作原理 ...44
第四章研究結果與討論 48
4.1模擬分析結果 48
4.1.2量測電極選用 48
4.1.3 理論分析 51
4.1.4模擬與實驗佐證 52
4.1.5微流體裝置電位與電場以及電滲透流分佈情形 55
4-2實驗結果 62
4.2.1收斂型微流體裝置的收集情形 62
4.2.2奈米線尺寸微流體裝置對於螢光分子收集情形 66
4.2.3奈米流道堵塞對電雙層之影響 69
第五章結論與未來工作 73
5.1 結論 73
5.2未來工作 74
參考文獻 75

[1] C.-M. Ho and Y.-C. Tai, "MICRO-ELECTRO-MECHANICAL-SYSTEMS (MEMS) AND FLUID FLOWS," Annual Review of Fluid Mechanics, vol. 30, pp. 579-612, 1998.
[2] K. Komvopoulos, "Surface engineering and microtribology for microelectromechanical systems," Wear, vol. 200, pp. 305-327, 12/1/ 1996.
[3] H. A. Stone, A. D. Stroock, and A. Ajdari, "ENGINEERING FLOWS IN SMALL DEVICES," Annual Review of Fluid Mechanics, vol. 36, pp. 381-411, 2004.
[4] E. Verpoorte and N. F. de Rooij, "Microfluidics meets MEMS," Proceedings of the IEEE, vol. 91, pp. 930-953, 2003.
[5] Anderson NL, The Human Plasma Proteome: History, Character, and Diagnostic Prospects. Molecular & Cellular Proteomics 1: 845-867, 2002.
[6] http://www.nanosilver.com.my/nanotech.asp
[7] Russel WB, Saville DA, Schowalter WR, Colloid Science: Principles and Applied Mathematics. Cambridge University Press, 1989.
[8] Hunter RJ, Zeta Potential in Colloid Science: Principles and Applications. Academic Press, New York 8: 386, 1981.
[9] D. P. J. Barz and P. Ehrhard, "Model and verification of electrokinetic flow and transport in a micro-electrophoresis device," Lab on a Chip, vol. 5, pp. 949-958, 2005.
[10] R. B. Schoch, J. Han, and P. Renaud, "Transport phenomena in nanofluidics," Reviews of Modern Physics, vol. 80, pp. 839-883, 07/17/ 2008.
[11] P. Attard, D. Antelmi, and I. Larson, "Comparison of the Zeta Potential with the Diffuse Layer Potential from Charge Titration," Langmuir, vol. 16, pp. 1542-1552, 2000/02/01 2000.
[12] A. Van Theemsche, J. Deconinck, B. Van den Bossche, and L. Bortels, "Numerical Solution of a Multi-Ion One-Potential Model for Electroosmotic Flow in Two-Dimensional Rectangular Microchannels," Analytical Chemistry, vol. 74, pp. 4919-4926, 2002/10/01 2002.
[13] http://www.kirbyresearch.com/index.cfm/wrap/textbook/microfluidicsna nofluidicsch6.html
[14] A.Tiselius, “A new apparatus for electrophoretic analysis of colloidal mixtures,”Trans Faraday Soc.,Vol. 33,pp. 524-531,(1951)
[15] H. Morgan, N. G. Green, “Ac electrokinetics: colloids and nanoparticles,”
Research Studies Press, (2003).
[16] Kim SJ, Ko SH, Kang KH, Han J, Direct seawater desalination by ion concentration polarization. Nature Nanotechnology 5: 297-301, 2010.
[17] "Book Reviews," Polymer News, vol. 29, pp. 327-328, 2004/10/01 2004.
[18] Gebauer P, Bocek P, Recent progress in capillary isotachophoresis. Electrophoresis 23: 3858–3864, 2002.
[19] Swerdlow JA-WH, Fluidic Preconcentrator Device for Capillary Electrophoresis of Proteins. Analytical Chemistry 75: 5207-5212, 2003.
[20] Burgi DS, Chien RL, Optimization in Sample Stacking for High-Performance
Capillary Electrophoresis. Analytical Chemistry 63: 2042-2047, 1991.
[21] Cui HC, Horiuchi K, Dutta P, Ivory CF, Multistage isoelectric focusing in a polymeric microfluidic chip. Analytical Chemistry 77: 7878-7886, 2005.
[22] Jung B, Bharadwaj R, Santiago JG, On-chip millionfold sample stacking using transient isotachophoresis. Analytical Chemistry 78: 2319-2327, 2006.
[23] Song S, Singh AK, Kirby BJ, Electrophoretic concentration of proteins at
laser-patterned nanoporous membranes in microchips. Analytical Chemistry 76:4589-4592, 2004.
[24] Khandurina J, Jacobson SC, Waters LC, Foote RS, Ramsey JM, Microfabricated porous membrane structure for sample concentration and electrophoretic analysis. Analytical Chemistry 71: 1815-1819, 1999.
[25] Pu QS, Yun JS, Temkin H, Liu SR, Ion-enrichment and ion-depletion effect of nanochannel structures. Nano Letters 4: 1099-1103, 2004.
[26] Wang Y-C, Stevens AL, Han J, Million-fold Preconcentration of Proteins and Peptides by Nanofluidic Filter. Analytical Chemistry 77: 4293-4299, 2005.
[27] S. J. Kim, Y.-C. Wang, J. H. Lee, H. Jang, and J. Han, "Concentration Polarization and Nonlinear Electrokinetic Flow near a Nanofluidic Channel," Physical Review Letters, vol. 99, p. 044501, 07/25/ 2007.
[28] S. M. Rubinstein, G. Manukyan, A. Staicu, I. Rubinstein, B. Zaltzman, R. G. H. Lammertink, et al., "Direct Observation of a Nonequilibrium Electro-Osmotic Instability," Physical Review Letters, vol. 101, p. 236101, 12/02/ 2008.
[29] S. J. Kim, L. D. Li, and J. Han, "Amplified Electrokinetic Response by Concentration Polarization near Nanofluidic Channel," Langmuir, vol. 25, pp. 7759-7765, 2009/07/07 2009.
[30] S. J. Kim and J. Han, "Self-Sealed Vertical Polymeric Nanoporous-Junctions for High-Throughput Nanofluidic Applications," Analytical Chemistry, vol. 80, pp. 3507-3511, 2008/05/01 2008.
[31] Kim SJ, Li LD, Han J, Multiplexed Proteomic Sample Preconcentration Device Using Surface-Patterned Ion-Selective Membrane. Lab on a Chip 8: 596-601, 2008.
[32] 趙晨喬, "稀薄濃度的生化樣品預濃縮之研究," 碩士, 工程科學系碩博士班, 國立成功大學, 台南市, 2012.
[33] Yu H, Lu Y, Zhou YG, Wang FB, He FY, et al., A simple, disposable microfluidic device for rapid protein concentration and purification via direct-printing. Lab on a Chip 8: 1496-1501, 2008.
[34] Kim SJ, Song YA, Han J, Nanofluidic concentration devices for biomolecules
utilizing ion concentration polarization: theory, fabrication, and applications.
Chemical Society Reviews 39: 912-922, 2010.
[35] P.M. Gresho and R.L. Sani, Incompressible Flow and the Finite Element Method, Volume 2: Isothermal Laminar Flow, John Wiley and Sons, LTD, 2000.
[36] I. Harari and T.J.R. Hughes, “What are C and h? Inequalities for the analysis and design of finite element methods,” Comp. Meth. Appl. Mech. Engrg, vol. 97, pp. 157–192, 1992.
[37] Y. Bazilevs, V.M. Calo, T.E. Tezduyar, and T.J.R. Hughes, “YZβ discontinuity capturing for advection-dominated processes with application to arterial drug delivery,” Int.J.Num. Meth. Fluids, vol. 54, pp. 593–608, 2007.
[38] T.J.R. Hughes and M. Mallet, “A new finite element formulation for computational fluid dynamics: III. The Generalized Streamline Operator for Multidimensional Advective-Diffusive System,” Comp. Meth. Appl. Mech. Engrg, vol. 58, pp. 305–328, 1986.
[39] G. Hauke and T.J.R. Hughes, “A unified approach to compressible and incompressible flows” Comp. Meth. Appl. Mech. Engrg, vol. 113, pp. 389–395, 1994.
[40] G. Hauke, “Simple stabilizing matrices for the computation of compressible flows in primitive variables,” Comp. Meth. Appl. Mech. Engrg, vol. 190, pp. 6881–6893, 2001.
[41] J.M. MacInnes, “Computation of Reacting Electrokinetic Flow in Microchannel Geometries,” J. Chem. Eng. Sci., vol. 57, no. 21, pp. 4539–4558, 2002.
[42] R.F. Probstein, Physicochemical Hydrodynamics, Wiley-Interscience, 1994.
[43] W. Menz, J. Mohr, and O. Paul, Microsystems Technology, Wiley-VCH Verlag GmbH, 2001.
[44] A. Soulaïmani and M. Fortin, “Finite element solution of compressible viscous flows using conservative variables,” Comp. Meth. Appl. Mech. Engrg, vol. 118, pp. 319–350, 2001.
[45] J.M. Coulson and J.F. Richardson, “Particle Technology and Separation Processes,” Chemical Engineering, vol. 2, Butterworth-Heinemann.
[46] 于華杰, 崔益民, and 王榮明, "聚焦離子束系統原理、應用及進展," 電子顯微學報, vol. 27, pp. 243-249, 2008.
[47] 徐宗偉, 房豐洲, 張少婧, and 陳耘輝, "基于聚焦離子束注入的微納加工技術研究," 電子顯微學報, vol. 28, pp. 62-67, 2009.
[48] 江素華, 謝進, and 王家楫, "新一代微分析及微加工手段--聚焦離子束系統," 電子工業專用設備, vol. 29, pp. 19-25, 2000.
[49] A review of focused ion beam applications in microsystem technologySteve Reyntjens and Robert Puers 2001 J. Micromech. Microeng. 11 287
[50] 章曉文, 林曉玲, and 陳嬡, "FIB的工作原理及其應用," 電子產品可靠性與環境試驗, vol. 27, pp. 4-10, 2009.
[51] http://en.wikipedia.org/wiki/Focused_ion_beam
[52] C.A.Volkert and A.M. Minor, “Focused Ion Beam Microscopy and Micromachining,” mrs bulletin, vol.32,may 2007
[53] D. S. Banks and C. Fradin, "Anomalous Diffusion of Proteins Due to Molecular Crowding," Biophysical Journal, vol. 89, pp. 2960-2971, 11// 2005.
[54] K. Ohsawa, M. Murata, and H. Ohshima, "Zeta potential and surface charge density of polystyrene-latex; comparison with synaptic vesicle and brush border membrane vesicle," Colloid and Polymer Science, vol. 264, pp. 1005-1009, 1986/12/01 1986.