Theoretical prediction of fast 3D AC electro-osmotic pumps.

AC electro-osmotic (ACEO) pumps in microfluidics currently involve planar electrode arrays, but recent work on the underlying phenomenon of induced-charge electro-osmosis (ICEO) suggests that three-dimensional (3D) geometries may be exploited to achieve faster flows. In this paper, we present some new design principles for periodic 3D ACEO pumps, such as the "fluid conveyor belt" of ICEO flow over a stepped electrode array. Numerical simulations of these designs (using the standard low-voltage model) predict flow rates almost twenty times faster than existing planar ACEO pumps, for the same applied voltage and minimum feature size. These pumps may enable new portable or implantable lab-on-a-chip devices, since rather fast (mm s(-1)), tuneable flows should be attainable with battery voltages (<10 V).

[1]  Cheng S. Lee,et al.  Direct control of the electroosmosis in capillary zone electrophoresis by using an external electric field , 1990 .

[2]  H. Morgan,et al.  Pumping of liquids with ac voltages applied to asymmetric pairs of microelectrodes. , 2003, Physical review. E, Statistical, nonlinear, and soft matter physics.

[3]  Parag A. Pathak,et al.  Massachusetts Institute of Technology , 1964, Nature.

[4]  D. Beebe,et al.  Physics and applications of microfluidics in biology. , 2002, Annual review of biomedical engineering.

[5]  Johannes Lyklema,et al.  Fundamentals of Interface and Colloid Science , 1991 .

[6]  Castellanos,et al.  Fluid flow induced by nonuniform ac electric fields in electrolytes on microelectrodes. I. Experimental measurements , 2000, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[7]  S. Quake,et al.  Monolithic microfabricated valves and pumps by multilayer soft lithography. , 2000, Science.

[8]  Hsueh-Chia Chang,et al.  Particle detection by electrical impedance spectroscopy with asymmetric-polarization AC electroosmotic trapping , 2005 .

[9]  A. Ewing,et al.  Electroosmotic flow control and surface conductance in capillary zone electrophoresis. , 1993, Analytical chemistry.

[10]  Zachary Gagnon,et al.  Aligning fast alternating current electroosmotic flow fields and characteristic frequencies with dielectrophoretic traps to achieve rapid bacteria detection , 2005, Electrophoresis.

[11]  M. Bazant,et al.  Induced-charge electrokinetic phenomena: theory and microfluidic applications. , 2003, Physical review letters.

[12]  S. Quake,et al.  Microfluidics: Fluid physics at the nanoliter scale , 2005 .

[13]  H. Stone,et al.  Microfluidics: Basic issues, applications, and challenges , 2001 .

[14]  I. Mezić,et al.  Chaotic Mixer for Microchannels , 2002, Science.

[15]  M. Mpholo,et al.  Low voltage plug flow pumping using anisotropic electrode arrays , 2003 .

[16]  A. Ewing,et al.  Electroosmotic flow control and monitoring with an applied radial voltage for capillary zone electrophoresis. , 1992, Analytical chemistry.

[17]  Howard A. Stone,et al.  Effective slip in pressure-driven Stokes flow , 2003, Journal of Fluid Mechanics.

[18]  Wei Wu,et al.  A compact dual-tip STM design , 2006, IEEE Transactions on Nanotechnology.

[19]  G. Whitesides,et al.  Soft lithography in biology and biochemistry. , 2001, Annual review of biomedical engineering.

[20]  M. Bazant,et al.  Breaking symmetries in induced-charge electro-osmosis and electrophoresis , 2005, Journal of Fluid Mechanics.

[21]  Laurits Højgaard Olesen,et al.  ac electrokinetic micropumps: the effect of geometrical confinement, Faradaic current injection, and nonlinear surface capacitance. , 2006, Physical review. E, Statistical, nonlinear, and soft matter physics.

[22]  Darwin R. Reyes,et al.  Micro total analysis systems. 1. Introduction, theory, and technology. , 2002, Analytical chemistry.

[23]  V. Studer,et al.  Fabrication of microfluidic devices for AC electrokinetic fluid pumping , 2002 .

[24]  A. Ajdari,et al.  Pumping liquids using asymmetric electrode arrays , 2000, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[25]  Castellanos,et al.  AC Electric-Field-Induced Fluid Flow in Microelectrodes. , 1999, Journal of colloid and interface science.

[26]  Jiehong Wu.  Biased AC electro-osmosis for on-chip bioparticle processing , 2006, IEEE Transactions on Nanotechnology.

[27]  Castellanos,et al.  Fluid flow induced by nonuniform ac electric fields in electrolytes on microelectrodes. II. A linear double-layer analysis , 2000, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[28]  V. Studer,et al.  An integrated AC electrokinetic pump in a microfluidic loop for fast and tunable flow control. , 2004, The Analyst.

[29]  Hsueh-Chia Chang,et al.  Long-Range AC Electroosmotic Trapping and Detection of Bioparticles , 2005 .

[30]  A. Rennie,et al.  Pumping of water with ac electric fields applied to asymmetric pairs of microelectrodes. , 2000, Physical review. E, Statistical, nonlinear, and soft matter physics.

[31]  M. Bazant,et al.  Diffuse-charge dynamics in electrochemical systems. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[32]  M. Bazant,et al.  Induced-charge electro-osmosis , 2003, Journal of Fluid Mechanics.

[33]  V. Studer,et al.  Experimental observation of induced-charge electro-osmosis around a metal wire in a microchannel , 2005 .

[34]  A. Stemmer,et al.  Electro-osmotic streaming on application of traveling-wave electric fields. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[35]  H. Morgan,et al.  Pumping of liquids with traveling-wave electroosmosis , 2005 .

[36]  H. Morgan,et al.  Ac electrokinetics: a review of forces in microelectrode structures , 1998 .

[37]  G. Whitesides,et al.  Flexible Methods for Microfluidics , 2001 .

[38]  R. Schasfoort,et al.  Field-effect flow control for microfabricated fluidic networks , 1999, Science.