Abstract
Controlling and manipulating liquids and analytes at the sub-millimeter scale is a challenge that frequently requires new methods to be developed. Indeed, scaling-down of traditional macroscopic ideas often fails. For instance, pumping liquids using pressure differences is often impractical and counterproductive because the resulting parabolic flow profile deforms sample zones. As the size of the system shrinks, the surface-to-volume ratio increases and interfacial effects become dominant. This actually opens new possibilities since the phenomenon of electroosmotic flow (EOF), wherein a fluid is made to move relative to a stationary charged boundary, can then be exploited to design efficient microfluidic devices. In this chapter, we review the fundamental principles of EOF as well as some of the methods used to coat channel walls and reduce the impact of EOF in situations where it would be unfavorable for the device performance.
This is a preview of subscription content, log in via an institution.
Buying options
Tax calculation will be finalised at checkout
Purchases are for personal use only
Learn about institutional subscriptionsSpringer Nature is developing a new tool to find and evaluate Protocols. Learn more
References
Russel, W. B., Saville, D. A. and Schowalter, W. R. (1989) Colloidal Dispersions. Cambridge University Press, New York.
Israelachvili, J. N. (1992) Intermolecular and Surface Forces. Academic Press, New York.
Behrens, S. H. and Grier, D. G. (2001) The charge of glass and silica surfaces. J. Chem. Phys. 115, 6716–6721.
Viovy, J.-L. (2000) Electrophoresis of DNA and other polyelectrolytes: physical mechanisms. Rev. Mod. Phys. 72, 813–872.
Rice, C. L. and Whitehead, R. (1965) Electrokinetic flow in a narrow cylindrical capillary. J. Phys. Chem. 69, 4017–4023.
Datta, R. and Kotamarthi, V. R. (1990) Electrokinetic dispersion in capillary electrophoresis. AICHE J. 36, 916–926.
Patankar, N. P. and Hu, H. H. (1998) Numerical Simulation of electroosmotic flow. Anal. Chem. 70, 1870–1881.
Berhens, S. H. and Borkovec, M. (1999) Electrostatic interaction of colloidal surfaces with variable charge. J. Phys. Chem. B 103, 2918–2928.
Burns, N. L., Emoto, K., Holmberg, K., Van Alstine, J. M., and Morris, J. M. (1998) Surface characterization of biomedical materials by measurement of electroosmosis. Biomaterials 19, 423–440.
Stone, H. A., Stroock, A. D., and Ajdari, A. (2004) Engineering flows in small devices: microfluidics towards a lab-on-a-chip. Annu. Rev. Fluid Mech. 36, 381–411.
Hjertén, S. (1985) High-performance electrophoresis – elimination of electroendoosmosis and solute adsorption. J. Chromatogr. 347, 191–198.
Albarghouthi, M. N., Stein, T. M., and Barron, A. E. (2003) Poly-N-hydroxyethylacrylamide as a novel, adsorbed coating for protein separation by capillary electrophoresis. Electrophoresis 24, 1166–1175.
Doherty, E. A. S., Meagher, R. J., Albarghouthi, M. N., and Barron, A. E. (2003) Microchannel wall coatings for protein separations by capillary and chip electrophoresis. Electrophoresis 24, 34–54.
Birdi, K. S. (1997) Handbook of Surface and Colloid Chemistry. CRC Press LLC, New York, pp. 559–600.
Doherty, E. A. S., Berglund, K. D., Buchholz, B. A., Kourkine, I. V., Przybycien, T. M., Tilton, R. D., and Barron, A. E. (2002) Critical factors for high-performance physically adsorbed (dynamic) polymeric wall coatings for capillary electrophoresis of DNA. Electrophoresis 23, 2766–2776.
Williams, B. A. and Vigh, G. (1996) Fast, accurate mobility determination method for capillary electrophoresis. Anal. Chem. 68, 1174–1180.
Huang, X. Gordon, M. J., and Zare, R. N. (1988) Current-monitoring method for measuring the electroosmotic flow rate in capillary zone electrophoresis. Anal. Chem. 60, 1837–1838.
Chiari, M., Cretich, M., Damin, F., Ceriotti, L., and Consonni, R. (2000) New adsorbed coatings for capillary electrophoresis. Electrophoresis 20, 909–916.
Sassi, A., Barron, A. E., Alonso-Amigo, M. G., Hion, D. Y., Yu, J. S., Soane, D. S., Hooper, H. H. (1996) Electrophoresis of DNA in novel thermoreversible matrices. Electrophoresis 17, 1460–1469.
Liang, D., Song, L., Zhou, S., Zaitsev, V. S., and Chu, B. (1999) Poly(N-isopropylacrylamide)-g-poly(ethyleneoxide) for high resolution and high speed separation of DNA by capillary electrophoresis. Electrophoresis, 20, 2856–2863.
Heller, Ch. (2001) Principles of DNA separation with capillary electrophoresis. Electrophoresis 22, 629–643.
Ghosal, S. (2004) Fluid mechanics of electroosmotic flow and its effect on band broadening in capillary electrophoresis. Electrophoresis 25, 214–228.
Horvath, J. and Dolnik, V. (2001) Polymer wall coatings for capillary electrophoresis. Electrophoresis 22, 644–655.
Righetti, P.G., Gelfi, C., Verzola, B., and Castelletti, L. (2001) The state of dynamic coatings. Electrophoresis 22, 603–611.
Liu, C. Y. (2001) Stationary phases for capillary electrophoresis and capillary electrochromatography. Electrophoresis 22, 612–628.
Liu, C. Y. (2001) Stationary phases for capillary electrophoresis and capillary electrochromatography. Electrophoresis 22, 612–628.
Further Reading
The present chapter is a simple introduction to the physics of EOF and the control of EOF via polymer coating. The following references are highly recommended: (4) is perhaps the best review of the electrophoresis of macromolecules; (10) is a superb review of electrokinetic phenomena in microfluidic devices and covers more materials that we could explore here; (13) is an extensive review of polymer coating; (22) is a great survey of some of the mathematical aspects of EOF.
Acknowledgments
K.K. would like to acknowledge the financial support of the Natural Sciences and Engineering Research Council of Canada (NSERC) and of NATO for a postdoctoral fellowship. GWS would like to thank NSERC for a Discovery Grant. F.T. would like to thank the University of Ottawa for an admission scholarship.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2010 Humana Press, a part of Springer Science+Business Media, LLC
About this protocol
Cite this protocol
Slater, G.W., Tessier, F., Kopecka, K. (2010). The Electroosmotic Flow (EOF). In: Hughes, M., Hoettges, K. (eds) Microengineering in Biotechnology. Methods in Molecular Biology, vol 583. Humana Press, Totowa, NJ. https://doi.org/10.1007/978-1-60327-106-6_5
Download citation
DOI: https://doi.org/10.1007/978-1-60327-106-6_5
Published:
Publisher Name: Humana Press, Totowa, NJ
Print ISBN: 978-1-58829-381-7
Online ISBN: 978-1-60327-106-6
eBook Packages: Springer Protocols