Micro-PIV measurements of induced-charge electro-osmosis around a metal rod

  • 824 Accesses

  • 17 Citations


A cylindrical gold-coated stainless steel rod was positioned at the center of a straight microchannel connecting two fluid reservoirs on either end. The microchannel was filled with 1 mM KCl containing 0.5 μm diameter carboxylate-modified spherical particles. Induced-charge electro-osmotic (ICEO) flow occurred around the metallic rod under a sinusoidal AC electric field applied using two platinum electrodes. The ICEO flows around the metallic rod were measured using micro particle image velocimetry (micro-PIV) technique as functions of the AC electric field strength and frequency. The present study provides experimental data about ICEO flow in the weakly nonlinear limit of thin double layers, in which, the charging dynamics of the double layer cannot be presented analytically. The measured ICEO flow pattern qualitatively agrees with the theoretical results obtained by Squires and Bazant (J Fluid Mech 509:217–252, 2004). Flow around the rod is quadrupolar, driving liquid towards the rod along the electric field and forcing it away from the rod in the direction perpendicular to the imposed electric field. The measured ICEO flow velocity is proportional to the square of the electric field strength, and depends on the applied AC frequency.

This is a preview of subscription content, log in to check access.

Access options

Buy single article

Instant unlimited access to the full article PDF.

US$ 39.95

Price includes VAT for USA

Subscribe to journal

Immediate online access to all issues from 2019. Subscription will auto renew annually.

US$ 99

This is the net price. Taxes to be calculated in checkout.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8


  1. Adrian RJ, Westerweel J (2011) Particle image velocimetry. Cambridge University Press, New York

  2. Ai Y, Joo SW, Jiang Y, Xuan X, Qian S (2009) Transient electrophoretic motion of a charged particle through a converging-diverging microchannel: effect of direct current dielectrophoretic force. Electrophoresis 30:2499–2506

  3. Ai Y, Park S, Zhu J, Xuan X, Beskok A, Qian S (2010) DC electrokinetic particle transport in an L-shaped microchannel. Langmuir 26(4):2937–2944

  4. Bazant MZ, Squiress TM (2010) Induced-charge electrokinetic phenomena. Curr Opin Colloid Interface Sci 15:203–213

  5. Bazant MZ, Kilic MS, Storey BD, Ajdari A (2009) Towards an understanding of induced-charge electrokinetics at large applied voltages in concentrated solutions. Adv Colloid Interface Sci 152:48–88

  6. Chang HS, Yeo LY (2010) Electrokinetically driven microfluidics and nanofluidics. Cambridge University Press, New York

  7. Duffy DC, McDonald JC, Schueller OJA, Whitesides GM (1998) Rapid prototyping of microfluidic systems in poly(dimethylsiloxane). Anal Chem 70:4974–4984

  8. Green NG, Ramos A, González A, Morgan H, Castellanos A (2000) Fluid flow induced by nonuniform ac electric fields in electrolytes on microelectrodes. I. Experimental measurements. Phys Rev E 61:4011–4018

  9. Green NG, Ramos A, González A, Castellanos A, Morgan H (2002) Fluid flow induced by nonuniform ac electric fields in electrolytes on microelectrodes. III. Observation of streamlines and numerical simulation. Phys Rev E 66:026305

  10. Harnett CK, Templeton J, Dunphy-Guzman KA, Senousya YM, Kanouff MP (2008) Model based design of a microfluidic mixer driven by induced charge Electroosmosis. Lab Chip 8:565–572

  11. Hu N, Ai Y, Qian S (2012) Field effect control of electrokinetic transport in micro/nanofluidics. Sensors Actuators B Chemical 161(1):1150–1167

  12. Hunter RJ (1981) Zeta potential in colloid science: principles and applications. Academic Press Inc, New York

  13. Karniadakis G, Beskok A, Aluru N (2005) Microflows and nanoflows: fundamental and simulation. Springer, New York

  14. Kim MJ, Beskok A, Kihm KD (2002) Electro-osmosis-driven micro-channel flows: a comparative study of microscopic particle image velocimetry measurements and numerical simulations. Exp Fluids 3:170–180

  15. Levitan JA, Devasenathipathy S, Studer V, Ben Y, Thorsen T, Squires TM, Bazant MZ (2005) Experimental observation of induced-charge electro-osmosis around a metal wire in a microchannel. Colloids Surf A Physicochem Eng Aspects 267:122–132

  16. Lindken R, Rossi M, Große S, Westerweel J (2009) Micro-particle image velocimetry (mPIV): recent developments, applications, and guidelines. Lab Chip 9:2551–2567

  17. Lyklema J (1995) Fundamentals of interface and colloid science, vol II, Solid-liquid interfaces. Academic Press Inc, London

  18. Mansuripur T, Pascall AJ, Squires TM (2009) Asymmetric flows over symmetric surfaces: capacitive coupling in induced-charge electro-osmotic flows. New J Phys 1:075030

  19. Meinhart CD, Wereley ST, Santiago JG (1999) PIV measurements of a microchannel flow. Exp Fluids 27:414–419

  20. Morgan H, Green NG (2003) AC Electrokinetics: colloids and nanoparticles. Research Studies Press LTD, Philadelphia

  21. Park S, Beskok A (2008) Alternating current electrokinetic motion of colloidal particles on interdigitated microelectrodes. Anal Chem 80(8):2831–2841

  22. Park S, Koklu M, Beskok A (2009) Particle trapping in high-conductivity media with electrothermally enhanced negative dielectrophoresis. Anal Chem 81(6):2303–2310

  23. Pascall AJ, Squires TM (2010a) Induced charge electro-osmosis over controllably contaminated electrodes. Phys Rev Lett 104:088301

  24. Pascall AJ, Squires TM (2010b) An automated, high-throughput experimental system for induced charge electrokinetics. Lab Chip 10:2350–2357

  25. Raffel M, Willert CE, Wereley ST, Kompenhans J (2007) Particle image velocimetry: a practical guide, 2nd edn. Springer, New York

  26. Sanchez PG, Ramos A, Gonzales A, Green NG, Morgan H (2009) Flow reversal in travelling-wave electrokinetics: an analysis of forces. Langmuir 25(9):4988–4997

  27. Santiago JG, Wereley ST, Meinhart CD, Beebe DJ, Adrian RJ (1998) A particle image velocimetry system for microfluidics. Exp Fluids 25:316–319

  28. Sharp KV, Yazdi SH, Davison S (2011) Localized flow control in microchannel using induced-charge electroosmosis near conductive obstacles. 10:1257–1267

  29. Squires TM (2009) Induced-charge electrokinetics: fundamental challenges and opportunities. Lab Chip 9:2477–2483

  30. Squires TM, Bazant MZ (2004) Induced-charge electro-osmosis. J. Fluid Mech 509:217–252

  31. Squires TM, Bazant MZ (2006) Breaking symmetries in induced-charge electro-osmosis and electrophoresis. J Fluid Mech 560:65–101

  32. Storey BD, Edwards LR, Kilic MS, Bazant MZ (2008) Steric effects on ac electro-osmosis in dilute electrolytes. Phys Rev E 77:036317

  33. Studer V, Pépin A, Chen Y, Ajdari A (2004) An integrated ac electrokinetic pump in a microfluidic loop for fast tunable flow control. Analyst 129:944–949

  34. Wang D, Sigurdson M, Meinhart CD (2005) Experimental analysis of particle and fluid motion in ac electrokinetics. Exp Fluids 38:1–10

  35. Westerweel J (1997) Fundamentals of digital particle image velocimetry. Meas Sci Technol 8:1379–1392

  36. Westerweel J, Geelhoed PF, Lindken R (2004) Single-pixel resolution ensemble correlation for micro-PIV applications. Exp Fluids 37:375–384

  37. Yalcin SE, Sharma A, Qian S, Joo SW, Baysal O (2010) Manipulating particles in microfluidics by floating electrodes. Electrophoresis 31:3711–3718

  38. Yalcin SE, Sharma A, Qian S, Joo SW, Baysal O (2011) On-demand particle enrichment in a microfluidic channel by a locally controlled floating electrode. Sensors Actuators B Chem 153:277–283

  39. Zhang M, Ai Y, Sharma A, Joo SW, Kim D-S, Qian S (2011) Electrokinetic particle translocation through a nanopore containing a floating electrode. Electrophoresis 32:1864–1874

  40. Zhao H, Bau HH (2007) Microfluidic chaotic stirrer utilizing induced-charge electro-osmosis. Phys Rev E 75:066217

Download references


Canpolat C. acknowledges the financial support of The Scientific and Technological Research Council of Turkey (TUBITAK) for this study.

Author information

Correspondence to Ali Beskok.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (mpg 1418 kb)

Supplementary material 1 (DOCX 2585 kb)

Supplementary material 1 (mpg 1418 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Canpolat, C., Qian, S. & Beskok, A. Micro-PIV measurements of induced-charge electro-osmosis around a metal rod. Microfluid Nanofluid 14, 153–162 (2013) doi:10.1007/s10404-012-1033-4

Download citation


  • Conductive cylinder
  • Induced-charge electro-osmosis
  • Vortex
  • Micro-PIV