本研究利用微機電製程技術，製作出奈米管道與微米管道，再將晶片對位並置入高溫爐完成熔融接合。當施加電壓於奈微米晶片內部時，由於奈米管道內部電雙層重疊現象，使得奈米管道內部具有離子選擇特性，此特性造成奈米管道內部正、負離子通量之差異，並在奈微米交界處產生濃度極化效應。本文主要探討兩部分: (1) 利用模擬探討電解液濃度與表面電荷密度對奈米管道濃度極化效應之影響，並利用實驗探討不同pH值對濃度極化之影響。(2) 奈米管道附近之非線性電動現象。
第一部分，由於電雙層重疊效應與電解液濃度和表面電荷密度有密切關係，本論文利用模擬2-D奈微米管道，探討在不同電解液濃度與不同表面電荷密度的情形下，使管道內部產生濃度極化時，所需施加之電壓。由模擬結果可知，當濃度越稀、表面電荷密度越大時，使管道內部產生濃度極化的電壓則越小，此外利用實驗探討當電解液NaCl濃度為10-4M在不同pH值下，進行S曲線之電性量測，由實驗結果可知，當pH值越高時，使管道內部產生濃度極化的電壓則越小，而當pH值較低時，所量測到之電流值亦降低。
第二部分，利用電雙層重疊效應，使得奈米管道(鈉玻璃基材)內部正離子通量遠大於負離子。當施加電壓於奈微米管道時，造成管道高電位端產生離子排斥現象，於低電位端產生離子聚集現象。濃度極化效應會造成局部離子空乏現象，並使得管道內部產生濃度梯度。本論文利用管道類比電阻概念，估算離子排斥區域內電導率與電場強度。此外置入螢光微粒於管道內部，探討在不同電壓下，螢光微粒在奈微米管道交界處流動之平均速度。由實驗結果可知，離子排斥區域內，由於電導率下降，使得此區域內電場將被放大並使流體速度增加，而管道內部為滿足質量守恆，在奈微米管道介面處會產生背壓來平衡這流量上的差異，並在奈微米管道介面處附近產生渦流，此對稱渦流速度也隨著電壓增加而變快。

In this work, we present an experimental and numerical investigation on the concentration polarization in hybrid micro/nanochannels. Two issues were investigated: (1) pH value effect on the occurrence of concentration polarization and the I-V curve (i.e. S curve) and (2) nonlinear electrokinetic flow at the interface between micro/nanochannels.
In the first part of this thesis, we explore the voltage required to impose, in different concentration of electrolyte and surface charge density, so that the concentration polarization within channel occured. Results show that the low concentration of the electrolyte and high surface charge density will occur concentration polarization under low voltage. In addition, the experimental results showed that the applied voltage required to produce the concentration polarization decreases with increasing the pH value of the electrolyte.
The second part of this thesis focuses on the flow near the interface of micro/nanochannel. We utilized electrical measurements and evaluated the electrical conductivity and the electrical field within the depletion region. Fluorescent particles are injected into the channel to observe flow field near nano/microchannel interface. Results show that the electrical conductivity were decreased and the electrical field were increased in depletion region and fast fluid vortices were generated at the anodic side of the nanochannel due to the nonequilibrium electroosmotic flow.

[01] Vorst, O., Kok E. J., Peijnenburg A, Aharoni A, Van Tunen A. J., Keijer J, Van H. A., Van H. N., “The application of DNA microarrays in gene expression analysis ” , Journal of Biotechnology, 78, 271-280, 2000.
[02] Erill, I, Villa, R, Goudignon, P, Fonseca, L, Plaza, JA ,“Silicon microsystem passivation for high-voltage applications in DNA chips”, Microeletronics and Reliability, 40, 787-789, 2000.
[03] Manz, A., Harrison, DJ, Verpoorte, E. M. J., Fetitinger, J. C., Paulus, A., Widmer, H. M. “Planar chips technology for miniaturization and integration of separation techniques into monitoring systems-capillary electrophoresis on a chip”, Journal of Chromatography A, 593, 253-258, 1992.
[04] Manzs, A., Graber, N., Widmer, H. M., Actuators B1, 244-248, 1990
[05] Trieu, H. K., Ewe, L., Mokwa, W., Schwarz, M., and Hosticka, B. J., “Flexible silicon structures for a retina implant ”, IEEE MEMS 98, 515-519, 1998
[06] Reyes, D. R., Lossifidis D., Auroux P. A. and Manz, A., “Micro total analysis system Ι : introduction, theory and technology”, Analytical Chemistry, 74, 2623-2636, 2002
[07] Gravesen, P., Branebjerg O. J. and Jensen, S. “Microfluidic- a review”, Journal of Micromechanics and Microengineering, 3, 168-182, 1993.
[08] Harrison, D. J. and Berg, A., “Micro Total Analysis System 98”, Kluwer Academic Publishers, Netherland 1998.
[09] Shoji, S., “Microfabrication technologies and micro-flow devices for chemical and bio-chemical micro flow system”, Microprocesses and Nanotechnology, 99, 72-73, 1999
[10] Chang, C. C., Yang, R. J., “A particle tracking method for analyzing chaotic electroosmotic flow mixing in 3-D microchannels with patterned charged surfaces”, Journal of Micromechanics and Microengineering, 16, 1453-1462, 2006.
[11] Russel, W. B., Saville, D. A. and Schowalter, W. R. Colloid science : principle and applied mathematics, Cambridge University Press, Cambridge, 1989.
[12] Hunter, R. J., Zeta potential in colloid science: Principles and applications, academic press, New York, 1981.
[13] Probstein, R. F. Physicochemical hydrodynamics: an introduction , John Wiley and Sons, New York, 1994.
[14] Yang, R. J., Fu, L. M., Lin Y. C., “Electroosmotic entry flow in microchannels”, Journal of Colloid and Interface Science, 239, 98-105, 2001.
[15] Lyklema, J., “Electrokinetics after smoluchowski”, Colloids and Surface a-Physicochemical and Engineer Aspects, 222, 5-14 , 2003.
[16] Patankar, N. A., Hu, H. H., “Numerical simulation of electroosmotic flow”, Analytical Chemistry, 70, 1870-1881. 1998.
[17] Wu, J.T., Du, J. R., Juang, Y. J. and Wei, H.H. ”Rectified elongational streaming due to asymmetric electro-osmosis induced by ac polarization”, Applied Physics Letters 90, 134103, 2007.
[18] Wu, J., ”Biased AC Electro-Osmosis for On-Chip Bioparticle Processing”, IEEE Transactions on nanotechnology, 5, 84-89, 2006.
[19] Yang, C., Li, D. and Masliyah, J. H., “Modeling forced liquid convection in rectangular microchannels with electrokinetic effects”, International Journal of Heat and Mass Transfer, 41, 4229-4249 , 1998.
[20] Van, T.G.M., Ven, de, Colloidal hydrodynamics. Academic Press, San Diego, 1989.
[21] Babeshko, V. A., Zabolotskii, V. I., Korzhenko, N. M., Seidov, R. R., and Urtenov, M. K., ”Decomposition of non-one-dimensional system of Nernst-Plank-Poisson equations”, Doklady Akademii Nauk, 361, 45-46, 1998.
[22] Jin, X. Z., Joseph, S., Gatimu, E. N., Bohn, P. W., and Aluru, N. R., ”Induced electrokinetic transport in micro-nanofluidic interconnect devices”, Langmuir 23 , 13209-13222, 2007.
[23] Gross, R.J. and Osterle, J.F., “Membrane transport characteristic of ultrafine capillaries”, Journal of Chemical Physics , 49, 228-234, 1968.
[24] Plecis, A., Schoch, R.B. and Renaud, P. “Ionic transport phenomena in nano- fluidics: Experimental and theoretical study of the exclusion-enrichment effect on a chip”, Nano Letters, 5, 1147-1155, 2005.
[25] Lin, G. H., Lee, G. B., Lin, Y. H. and Chang, G. L., “A fast prototyping process for fabrication of microfluidic system on soda-lime glass”, Journal Microme- chanics and Microengineering, 11, 726-732, 2001.
[26] Rubinstein, I. and Htilman, L. “Voltage against current curves of cation exchange membranes”, Chemical Science, 231-246, 1979.
[27] Barragan, V. M. and Ruız-Bauza, C. “Current-voltage curves for ion-exchange membranes: A method for determining the limiting current density”, Journal of Colloid and Interface Science, 205, 365-373, 1998.
[28] Rubinstein, I. and Zaltzman, B. “Electro-osmotically induced convection at a permselective membrane”, Physical Review E, 62, 2238-2251, 2000.
[29] Yossifon, G., Mushenheim, P., Chang, Y.C., and Chang H. C., “Nonlinear current-voltage characteristics of nanochannels”, Physical Review E, 79, 046305, 2009.
[30] Dukhin, S. S., “Electrokinetic phenomena of the second kind and their applications”, Advances in Colloid and Interface Science, 35, 173-196, 1991
[31] Dukhin, S. S., and Mishchuk, NA (1993). “Intensification of electrodialysis based on electroosmosis of the 2nd kind”, Journal of Membrane Science, 79, 199-210, 1993.
[32] Ben, Y., and Chang, H. C. (2002). “ Nonlinear Smoluchowski slip velocity and micro-vortex generation”, Journal of Fluid Mechanics, 461, 229-238, 2002
[33] Taskhistov, P., Duginova, K., Chang, H. C., “Electrokinetic mixing vortices due to electrolyte depletion at microchannel junctions”, Journal of Colloid and Interface Science, 263, 133-143, 2003.
[34] Kim, S. J., Wang, Y. C., Lee, J. H., Hongchul, J. and Han, J. “Concentration polarization and nonlinear electrokinetic Flow near a Nanofluidic Channel”, Physical Review Letter, 99, 044501, 2007.
[35] Kim, S. J., Li, D. L. and Han, J., “Amplified electrokinetic response by concen- tration polarization near nanofluidic channel”, Langmuir, 2009.
[36] Pu, Q. S., Yun, J. S., Temkin, H., and Liu, S. R., “Ion-enrichment and ion deple- tion effect of nanochannel structures”, Nano Letter, 4, 1099-1103, 2004.