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Flow instability and scaling transition near strongly polarised surfaces

Published online by Cambridge University Press:  26 November 2025

Wei Liu ,
Yunfan Huang  and
Moran Wang Open the ORCID record for Moran Wang [Opens in a new window]
Wei Liu
Affiliation:
Department of Engineering Mechanics and ASP, Tsinghua University , Beijing 100084, PR China
Yunfan Huang
Affiliation:
Department of Engineering Mechanics and ASP, Tsinghua University , Beijing 100084, PR China
Moran Wang*
Affiliation:
Department of Engineering Mechanics and ASP, Tsinghua University , Beijing 100084, PR China
*
Corresponding author: Moran Wang, moralwang@jhu.edu
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Abstract

The electrokinetic and unstable behaviour near strongly polarised surfaces cannot be well captured by the canonical asymptotic theory for induced-charge electro-osmosis, and the intrinsic mechanism remains unclear. Using direct numerical simulations and scaling analysis, this paper reveals that, near the strongly polarised surfaces, the strong electric double layer charging induces a strong local electric field, which drives the cations in the electrical double layer to extend to a finite region and form an extended space-charge (ESC) layer. The ESC triggers flow instability near strongly polarised surfaces, causing a transition of the velocity scaling exponent in the electric field dependence from a 2 to a 4/3 power law. The findings and mechanisms pave the way for designs of energy and biomedical systems.

JFM classification

MHD and Electrohydrodynamics: Electrokinetic flows

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Type
JFM Papers
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Journal of Fluid Mechanics , Volume 1024 , 10 December 2025 , A8
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© The Author(s), 2025. Published by Cambridge University Press

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References

Bazant, M.Z. & Squires, T.M. 2004 Induced-charge electrokinetic phenomena: theory and microfluidic applications. Phys. Rev. Lett. 92 (6), 066101.10.1103/PhysRevLett.92.066101CrossRefGoogle ScholarPubMed
Bazant, M.Z. & Squires, T.M. 2010 Induced-charge electrokinetic phenomena. Curr. Opin. Coll. Interface Sci. 15 (3), 203–213.10.1016/j.cocis.2010.01.003CrossRefGoogle Scholar
Bazant, M.Z., Thornton, K. & Ajdari, A. 2004 Diffuse-charge dynamics in electrochemical systems. Phys. Rev. E. 70 (2), 021506.10.1103/PhysRevE.70.021506CrossRefGoogle ScholarPubMed
Bazant, M.Z., Storey, B.D. & Kornyshev, A.A. 2011 Double layer in ionic liquids: overscreening versus crowding. Phys. Rev. Lett. 106 (4), 046102.10.1103/PhysRevLett.106.046102CrossRefGoogle ScholarPubMed
Chen, G., Perazzo, A. & Stone, H.A. 2020 Influence of salt on the viscosity of polyelectrolyte solutions. Phys. Rev. Lett. 124 (17), 177801.10.1103/PhysRevLett.124.177801CrossRefGoogle ScholarPubMed
Davidson, S.M., Andersen, M.B. & Mani, A. 2014 Chaotic induced-charge electro-osmosis. Phys. Rev. Lett. 112 (12), 128302.10.1103/PhysRevLett.112.128302CrossRefGoogle ScholarPubMed
Demekhin, E.A., Shelistov, V.S. & Polyanskikh, S.V. 2011 Linear and nonlinear evolution and diffusion layer selection in electrokinetic instability. Phys. Rev. E. 84 (3), 036318.10.1103/PhysRevE.84.036318CrossRefGoogle ScholarPubMed
Dukhin, S.S. 1991 Electrokinetic phenomena of the second kind and their applications. Adv. Coll. Interface Sci. 35, 173–196.10.1016/0001-8686(91)80022-CCrossRefGoogle Scholar
Gregersen, M.M., Andersen, M.B., Soni, G., Meinhart, C. & Bruus, H. 2009 Numerical analysis of finite debye-length effects in induced-charge electro-osmosis. Phys. Rev. E. 79 (6), 066316.10.1103/PhysRevE.79.066316CrossRefGoogle ScholarPubMed
Gu, Z.B., Xu, B.R., Huo, P., Rubinstein, S.M., Bazant, M.Z. & Deng, D.S. 2019 Deionization shock driven by electroconvection in a circular channel. Phys. Rev. Fluids 4 (11), 113701.10.1103/PhysRevFluids.4.113701CrossRefGoogle Scholar
Guan, Y.F., He, X.R., Wang, Q., Song, Z.W., Zhang, M.Q. & Wu, J. 2021 Monotonic instability and overstability in two-dimensional electrothermohydrodynamic flow. Phys. Rev. Fluids 6 (1), 013702.10.1103/PhysRevFluids.6.013702CrossRefGoogle Scholar
Gupta, A., Rallabandi, B. & Stone, H.A. 2019 Diffusiophoretic and diffusioosmotic velocities for mixtures of valence-asymmetric electrolytes. Phys. Rev. Fluids 4 (4), 043702.10.1103/PhysRevFluids.4.043702CrossRefGoogle Scholar
Harnett, C.K., Templeton, J., Dunphy-Guzman, K.A., Senousy, Y.M. & Kanouff, M.P. 2008 Model based design of a microfluidic mixer driven by induced charge electroosmosis. Lab Chip 8 (4), 565–572.10.1039/b717416kCrossRefGoogle ScholarPubMed
Kang, S. & Kwak, R. 2020 Pattern formation of three-dimensional electroconvection on a charge selective surface. Phys. Rev. Lett. 124 (15), 154502.10.1103/PhysRevLett.124.154502CrossRefGoogle ScholarPubMed
Karatay, E., Andersen, M.B., Wessling, M. & Mani, A. 2016 Coupling between buoyancy forces and electroconvective instability near ion-selective surfaces. Phys. Rev. Lett.. 116 (19), 194501.10.1103/PhysRevLett.116.194501CrossRefGoogle ScholarPubMed
Khair, A.S. & Balu, B. 2020 Breaking electrolyte symmetry in induced-charge electro-osmosis. J. Fluid Mechan. 905, A20.10.1017/jfm.2020.754CrossRefGoogle Scholar
Kim, J., Davidson, S. & Mani, A. 2019 Characterization of chaotic electroconvection near flat inert electrodes under oscillatory voltages. Micromachines 10 (3), 161.10.3390/mi10030161CrossRefGoogle ScholarPubMed
Kwak, R., Pham, V.S., Lim, K.M. & Han, J. 2013 Shear flow of an electrically charged fluid by ion concentration polarization: scaling laws for electroconvective vortices. Phys. Rev. Lett. 110 (11), 114501.10.1103/PhysRevLett.110.114501CrossRefGoogle ScholarPubMed
Lazo, I., Peng, C., Xiang, J., Shiyanovskii, S.V. & Lavrentovich, O.D. 2014 Liquid crystal-enabled electro-osmosis through spatial charge separation in distorted regions as a novel mechanism of electrokinetics. Nat. Commun. 5 (1), 5033.10.1038/ncomms6033CrossRefGoogle ScholarPubMed
Levitan, J.A., Devasenathipathy, S., Studer, V., Ben, Y., Thorsen, T., Squires, T.M. & Bazant, M.Z. 2005 Experimental observation of induced-charge electro-osmosis around a metal wire in a microchannel. Coll. Surfaces A: Physicochem. Engine. Aspects 267 (1), 122–132.10.1016/j.colsurfa.2005.06.050CrossRefGoogle Scholar
Li, G., Townsend, A., Archer, L.A. & Koch, D.L. 2022 Electroconvection near an ion-selective surface with Butler–Volmer kinetics. J. Fluid Mechan. 930 (A26), A26.10.1017/jfm.2021.907CrossRefGoogle Scholar
Liu, W., Zhou, Y. & Shi, P. 2020a Shear electroconvective instability in electrodialysis channel under extreme depletion and its scaling laws. Phys. Rev. E. 101 (4), 043105.10.1103/PhysRevE.101.043105CrossRefGoogle ScholarPubMed
Liu, W., Zhou, Y. & Shi, P. 2020b Scaling relations in shear electroconvective vortices. Phys. Fluids. 32 (7).10.1063/5.0015117CrossRefGoogle Scholar
Liu, W., Zhou, Y.T. & Shi, P.P. 2022 Critical selection of shear sheltering in electroconvective flow from chaotic to steady state. J. Fluid Mechan. 946, A3.10.1017/jfm.2022.557CrossRefGoogle Scholar
Liu, Z.J., Li, D., Song, Y.X., Pan, X.X., Li, D.Q. & Xuan, X.C. 2017 Surface-conduction enhanced dielectrophoretic-like particle migration in electric-field driven fluid flow through a straight rectangular microchannel. Phys. Fluids 29 (10), 102001.10.1063/1.4996191CrossRefGoogle Scholar
Mani, A. & Wang, K.M. 2020 Electroconvection near electrochemical interfaces: experiments, modeling, and computation. Ann. Rev. Fluid Mechan. 52 (1), 509–529.10.1146/annurev-fluid-010719-060358CrossRefGoogle Scholar
Messinger, R.J. & Squires, T.M. 2010 Suppression of electro-osmotic flow by surface roughness. Phys. Rev. Lett. 105 (14), 144503.10.1103/PhysRevLett.105.144503CrossRefGoogle ScholarPubMed
Oyarzun, D.I., Hemmatifar, A., Palko, J.W., Stadermann, M. & Santiago, J.G. 2018 Ion selectivity in capacitive deionization with functionalized electrode: theory and experimental validation. Water Res. X. 1, 100008.Google ScholarPubMed
Pascall, A.J. & Squires, T.M. 2010 Induced charge electro-osmosis over controllably contaminated electrodes. Phys. Rev. Lett. 104 (8), 088301.10.1103/PhysRevLett.104.088301CrossRefGoogle ScholarPubMed
Pascall, A.J. & Squires, T.M. 2011 Electrokinetics at liquid/liquid interfaces. J. Fluid Mechan. 684, 163–191.10.1017/jfm.2011.288CrossRefGoogle Scholar
Peng, C., Lazo, I., Shiyanovskii, S.V. & Lavrentovich, O.D. 2014 Induced-charge electro-osmosis around metal and Janus spheres in water: patterns of flow and breaking symmetries. Phys. Rev. E. 90 (5), 051002.10.1103/PhysRevE.90.051002CrossRefGoogle ScholarPubMed
Ramachandran, A., Hawks, S.A., Stadermann, M. & Santiago, J.G. 2018 Frequency analysis and resonant operation for efficient capacitive deionization. Water Res. 144, 581–591.10.1016/j.watres.2018.07.066CrossRefGoogle ScholarPubMed
Ramos, A., Morgan, H., Green, N.G. & Castellanos, A. 1998 Ac electrokinetics: a review of forces in microelectrode structures. J. Phys. D: Appl. Phys. 31 (18), 2338.10.1088/0022-3727/31/18/021CrossRefGoogle Scholar
Ramos, A., Morgan, H., Green, N.G. & Castellanos, A. 1999 AC electric-field-induced fluid flow in microelectrodes. J. Coll. Interface Sci. 217 (2), 420–422.10.1006/jcis.1999.6346CrossRefGoogle ScholarPubMed
Revil, A. & Linde, N. 2006 Chemico-electromechanical coupling in microporous media. J. Coll. Interface Sci. 302 (2), 682–694.10.1016/j.jcis.2006.06.051CrossRefGoogle ScholarPubMed
Revil, A., Ghorbani, A., Su, Z.Y., Cai, H.Z. & Hu, X.Y. 2024 Induced polarization of clay-rich materials - part 3: partially saturated mixtures of clay and pyrite. Geophysics 89 (3), E101–E112.10.1190/geo2023-0562.1CrossRefGoogle Scholar
Revil, A., Linde, N., Cerepi, A., Jougnot, D., Matthäi, S. & Finsterle, S. 2007 Electrokinetic coupling in unsaturated porous media. J. Coll. Interface Sci. 313 (1), 315–327.10.1016/j.jcis.2007.03.037CrossRefGoogle ScholarPubMed
Rubin, S., Suss, M.E., Biesheuvel, P.M. & Bercovici, M. 2016 Induced-charge capacitive deionization: the electrokinetic response of a porous particle to an external electric field. Phys. Rev. Lett. 117 (23), 234502.10.1103/PhysRevLett.117.234502CrossRefGoogle Scholar
Rubinstein, I. & Zaltzman, B. 2000 Electro-osmotically induced convection at a permselective membrane. Phys. Rev. E. 62 (2), 2238–2251.10.1103/PhysRevE.62.2238CrossRefGoogle Scholar
Rubinstein, I. & Zaltzman, B. 2001 Electro-osmotic slip of the second kind and instability in concentration polarization at electrodialysis membranes. Math. Models Methods Appl. Sci. 11 (02), 263–300.10.1142/S0218202501000866CrossRefGoogle Scholar
Rubinstein, I. & Zaltzman, B. 2003 Wave number selection in a nonequilibrium electro-osmotic instability. Phys. Rev. E. 68 (3), 032501.10.1103/PhysRevE.68.032501CrossRefGoogle Scholar
Schnitzer, O. & Yariv, E. 2012 Induced-charge electro-osmosis beyond weak fields. Phys. Rev. E. 86 (6), 061506.10.1103/PhysRevE.86.061506CrossRefGoogle ScholarPubMed
Squires, T.M. & Bazant, M.Z. 2004 Induced-charge electro-osmosis. J. Fluid Mechan. 509, 217–252.10.1017/S0022112004009309CrossRefGoogle Scholar
Squires, T.M. & Quake, S.R. 2005 Microfluidics: fluid physics at the nanoliter scale. Rev. Modern Phys. 77 (3), 977–1026.10.1103/RevModPhys.77.977CrossRefGoogle Scholar
Stone, H.A., Stroock, A.D. & Ajdari, A. 2004 Engineering flows in small devices: microfluidics toward a lab-on-a-chip. Ann. Rev. Fluid Mechan. 36, 381–411.10.1146/annurev.fluid.36.050802.122124CrossRefGoogle Scholar
Traoré, P. & Wu, J. 2013 On the limitation of imposed velocity field strategy for coulomb-driven electroconvection flow simulations. J. Fluid Mechan. 727, R3.10.1017/jfm.2013.267CrossRefGoogle Scholar
Xiao, C., Wang, X., Zhao, Y.M., Zhang, H.W., Song, J.Y., Vikesland, P., et al. 2024 DC vs AC electrokinetics-driven nanoplasmonic raman monitoring of charged analyte molecules in ionic solutions. J. Phys. Chem. C. 128 (36), 15103–15116.10.1021/acs.jpcc.4c04485CrossRefGoogle ScholarPubMed
Xu, B., Gu, Z., Liu, W., Huo, P., Zhou, Y., S., M. & Rubinstein,et al. 2020 Electro-osmotic instability of concentration enrichment in curved geometries for an aqueous electrolyte. Phys. Rev. Fluids 5 (9), 091701.10.1103/PhysRevFluids.5.091701CrossRefGoogle Scholar
Xuan, X.C., Sinton, D. & Li, D.Q. 2004 Thermal end effects on electroosmotic flow in a capillary. Intern. J. Heat Mass Transfer 47 (14–16), 3145–3157.10.1016/j.ijheatmasstransfer.2004.02.023CrossRefGoogle Scholar
Zaltzman, B. & Rubinstein, I. 2007 Electro-osmotic slip and electroconvective instability. J. Fluid Mechan. 579, 173–226.10.1017/S0022112007004880CrossRefGoogle Scholar