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Updated: Nov 6, 2025

Generation and Control of Electrohydrodynamic Flows in Aqueous Electrolyte Solutions
Published on: September 7, 2018
Structure and Dynamics of Electric-Field-Driven Convective Flows at the Interface between Liquid Electrolytes and
Alexander Warren1, Arpita Sharma1, Duhan Zhang2
1School of Chemical and Biomolecular Engineering, Cornell University, Ithaca, New York 14853, United States.
Abstract:
At voltages above a certain critical value, Vc ≈ 20 kT/e, a space charge layer forms near ion-selective interfaces in liquid electrolytes. Interactions between the space charge and an imposed electric field drives a hydrodynamic instability known as electroconvection. Through particle tracking velocimetry we experimentally study the structure and dynamics of the resultant electroconvective flow. Consistent with previous numerical simulations, we report that, following imposition of a sufficiently large voltage, electroconvection develops gradually as pairs of counter-rotating vortices, which nucleate at the interface between an ion-selective substrate and a liquid electrolyte. Depending on the imposed voltage and cell geometry, the vorticies grow to length scales of hundreds of micrometers. Electroconvective flows are also reported to be structured and multiscale, with the size ratio of the largest to the smallest observable vortices inversely proportional to the Debye screening length.
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