A microfluidic-driving array is reported in this paper for the multi-function manipulation of micro-scale biological sample based on the Alternating Current Electro Osmosis Flow, which is achieved by the design of the asymmetric electrode pairs array. The features of our proposed design can not only orient bio-objects but also convey them. The design, simulation and experimental results of this proposed AC electrokinetic manipulation chip are reported in this paper. The microfluidic-driving manipulation array is consisted of titanium electrodes layer and SiO2 dielectric layer on top, but the functional electrodes are exposed without the dielectric layer. The manipulation electrodes are composed of the asymmetric-pairs electrodes arranged in line and circle. All of them are embedded in the device chamber. The functional electrodes are driven by using a waveform generator that provides the sinusoidal wave excitation of 2 to 10 volts peak to peak. When the ac potentials are applied to these asymmetric electrodes, a uni-direction flow can be generated by the gradient of the electric field. Responding to the frequency of ac potentials applied, the net electroosmosis flow is induced to different direction that results from both capacity charging and faradic charging effects. Then, the bio-particles can be driven with the electroosmosis flow, be orient to the near functional electrodes, and conveyed. According to the design of our circularly arranged electrodes, the inside width of electrodes is smaller than the outside width. The flow velocity increases with the decrease of the electrode dimensions, while we keep the same ratios between the electrode widths. By the control of voltage and frequency applied to manipulation electrodes, the manipulation features of the microfluidic-driven bio-particles can be used for various applications. In this paper, we use micro-spheres (latex beads) of 8μm, which has the similar size to cells, as target objects and 50μM NaCl water solution as the experimental medium to demonstrate the manipulation functions.

一個微流體驅動之多功能操控陣列晶片使用交流電滲流來操控微米級生物樣本，藉由不對稱電極對的設計來達到驅動的效果。我們所設計的電極陣列不只能導引生物性目標物，更能輸送操控它到我們想要的地方。這裡所提出來的交流電動力操控晶片設計之模擬與實驗結果也在此篇論文中做討論。微流體驅動之操控陣列是由鈦金屬電極層以及氧化矽絕緣層所組成，而具有驅動能力的電極在微流道中沒有絕緣層覆蓋。整個操控陣列是由不對稱電極對以直線與圓形排列而成。且整體被包含在一個微流道腔室當中。驅動電極的交流電訊號源是使用波形產生器所提供，產生二到十伏特波峰對波峰的正弦波。當交流電訊號施加在不對稱電極上時，一個具有相同方向的流體被不對稱的電場所驅動出來。調控所施加的電訊號頻率，由於電容效應以及法拉第效應所造成的結果可使電滲流產生不同方向的靜流量。接著，所要操控的生物性樣本就會被電滲流所驅動，它們會被引導到啟動的電極上，並且被輸送到設定的標的位置。各種以微流體操控生物性樣本的方式可被應用在各種不同方面的研究。在這篇論文中，我們使用八微米的乳膠微粒子當作我們的操控目標物，大小近似於細胞等級，並以五十微莫耳的氯化鈉水溶液當作實驗液體，來呈現整個操控晶片的性能。

[1] T. Strick, J. -F. Allemand, V. Croquette, D. Bensimon, “The Manipulation of Single Biomolecules,” Physics Today, vol. 54, no. 10, pp. 46-60, October 2001.
[2] http://www.lionixbv.nl/
[3] C. Hammond, “Cellular and Molecular Neurobiology,” pp. 177-80, Academic Press, San Diego, 1996.
[4] Y. Suzuki, “Flexible Microgripper and its Application to Micro-Measurement of Mechanical and Thermal Properties,” Proc. IEEE MicroElectroMechanical Systems Workshop (MEMS’96), pp. 406-11, San Diego, California, USA, Feb. 11-15, 1996.
[5] C.-J. Kim, A. P. Pisano, R. S. Muller, M. G.. Lim, “Polysilicon Microgripper,” Technical Digest, IEEE Solid-State Sensor and Actuator Workshop, pp. 48-51, Hilton Head, SC, USA, June 4-7, 1990.
[6] C.-J. Kim, A. P. Pisano, R. S. Muller, “Silicon-Processed Overhanging Microgripper,” Journal of Microelectromechanical Systems, 1, 31-6 (1992).
[7] A. Ashkin, “History of Optical Trapping and Manipulation of Small-Neutral Particle, Atoms, and Molecules,” IEEE Journal of Selected Topics in Quantum Electronics, 6, 841-56 (2000).
[8] D. Baechi, J. Dual, R. Buser, “A high Density Microchannel Network with Integrated Valves and Photodiodes,” Proceeding of IEEE MicroElectroMechanical Systems Workshop (MEMS’01), pp. 463-6, Interlaken, Switzerland, Jan. 21-25, 2001.
[9] Chieh Chang, Chia-Fang Chiang, Cheng-Hsiang Liu and Cheng-Hsien Liu, “A lobster-sniffing-inspired method for micro-objects manipulation using electrostatic micro-actuators,” J. Micromechanics and Microengineering, 15(2005), pp.812-821
[10] F. Arai, D. Andou, T. Fukuda, “Adhesion Forces Reduction for Micro Manipulation Based on Micro Physics,” Proceedings of IEEE
[11] N. G. Green, A. Ramos and H. Morgan, “Ac electrokinetics: a survey of sub-micrometre particle dynamics,” J. Phys. D: Appl. Phys. 33 (2000) 632–641.
[12] W.B. Russel, D. A. Saville and W.R. Schowalter 1995 Colloidal Dispersions (Cambridge: Cambridge University Press).
[13] M. P. Hughes, “AC electrokinetics: applications for nanotechnology,” Nanotechnology 11 (2000) 124–132.
[14] H. Morgan, M. P. Hughes, and N. G. Green, “Separation of Submicron Bioparticles by Dielectrophoresis,” Biophysical Journal Volume 77 July 1999 516–525.
[15] Th. Schnelle, T. Muller, G. Fuhr, “Trapping AC octode field cages,” J. Elecrostatics 50 (2000) 17-29.
[16] J. Voldman, M. Toner, M.L Gray, M.A. Schmidt, “A Dielectrophoresis-Based Array Cytometer. Transducers '01, 322-325 (2001).
[17] J. Voldman, M. Toner, M.L Gray, M.A. Schmidt, “Quantitative design and analysis of single-particle dielectrophoretic traps”. Micro Total Analysis Syst. '00. (eds. A. van den Berg, W. Olthius & P. Bergveld) 431-434 (2000).
[18] Hsin-Yu Wu and Cheng-Hsien Liu, “An electrokinetic micromixer for micro-fluidic bio-chip application,” Master Thesis, Department of PME, NTHU, 2003.
[19] T. M. Squires and S. R. Quake, Rev. Mod. Phys. 77, 977 2005.
[20] A. Ramos, H. Morgan, N. G. Green, and A. Castellanos, “AC Electric-Field-Induced Fluid Flow in Microelectrodes,” J. Colloid interface Sci., vol. 217, pp. 420-422, 1999.
[21] A. Ajdari, Phys. Rev. E 61, R45 2000
[22] A. B. D. Brown, C. G. Smith, and A. R. Rennie, “Pumping of water with ac electric fields applied to asymmetric pairs of microelectrodes,” Phys. Rev. E, vol. 63, 016305, pp. 1-8, 2001.
[23] N. G. Green, A. Ramos, A. Gonzalez, H. Morgan, and A. Castellanos, Phys. Rev. E 66, 026305 2002.
[24] M. Mpholo, C.G. Smith, A.B.D. Brown, “Low voltage plug flow pumping using anisotropic electrode arrays” Sensors and Actuators B 92 (2003) 262–268
[25] V. Studer, A. Pepin, Y. Chen, and A. Ajdari, Analyst Cambridge, U.K. 129, 944 2004
[26] 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
[27] L. H. Olesen, H. Bruus, and A. Ajdari, Phys. Rev. E 73, 056313 2006
[28] John Paul Urbanski, Todd Thorsena, Jeremy A. Levitan and Martin Z. Bazant, “Fast ac electro-osmotic micropumps with nonplanar electrodes”, APPLIED PHYSICS LETTERS 89, 143508 2006
[29] Dmitri Lastochkin, Ronghui Zhou, Ping Wang, Yuxing Ben, and Hsueh-Chia Chang, “Electrokinetic micropump and micromixer design based on ac faradaic polarization”, JOURNAL OF APPLIED PHYSICS VOLUME 96, 2004
[30] Kuang-han Chu, et al. “A microsystem chip for the manipulation of bio-particles via ACelectrokinetics array”, Transducers’07 Conference, Lyon, France
[31] Desoize B, Gimonet D, Jardiller JC, “Cell culture as spheroids: an approach to multicellular resistance”, Anticancer Res. 1998 Nov-Dec; 18(6A):4147-58.
[32] Shih-Hao Huang, et al, ”AC Electroosmotic generated in-plane microvortices for stationary or continuous fluid mixing,” Transducers’07 Conference, Lyon, France
[33] Achim Van Theemsche, Johan Deconinck, Bart Van den Bossche, and Leslie Bortels, “Numerical Solution of a Multi-Ion One-Potential Model for Electroosmotic Flow in Two-Dimensional Rectangular Microchannels”, Anal. Chem., 2002, 74 (19), pp 4919–4926