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Updated: May 16, 2026

The Preparation of Electrohydrodynamic Bridges from Polar Dielectric Liquids

The Preparation of Electrohydrodynamic Bridges from Polar Dielectric Liquids

Published on: September 30, 2014

Maxwell-Wagner polarization and frequency-dependent injection at aqueous electrical interfaces.

Mitchell Desmond¹, Nicholas Mavrogiannis, Zachary Gagnon

¹Department of Chemical and Biomolecular Engineering, Johns Hopkins University, 221 Maryland Hall, 3400 North Charles Street, Baltimore, Maryland 21218, USA.

Physical Review Letters

|December 11, 2012

Summary

We discovered a new alternating current (AC) phenomenon causing frequency-dependent fluid displacement at liquid-liquid interfaces. The direction of fluid flow reverses based on electrical properties and AC frequency, explained by Maxwell-Wagner polarization.

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AC Electrokinetic Phenomena Generated by Microelectrode Structures

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Published on: July 28, 2008

Area of Science:

Electrokinetics
Fluid dynamics
Interfacial science

Background:

Liquid-liquid interfaces are crucial in microfluidics and chemical processes.
Controlling fluid behavior at these interfaces is essential for many applications.

Purpose of the Study:

To demonstrate a novel alternating current (AC) induced interfacial polarization and fluid displacement phenomenon.
To investigate the frequency-dependent nature of this fluid displacement at a liquid-liquid interface.

Main Methods:

Utilizing a microfluidic channel to flow two immiscible liquid streams side-by-side.
Applying an AC electric field perpendicular to the interface between the liquid lamellae.
Observing and analyzing fluid displacement across the interface as a function of AC frequency.

Main Results:

Demonstrated frequency-dependent fluid displacement at the liquid-liquid interface.
Observed high-conductivity fluid displacing into high-dielectric fluid at low frequencies.
Observed reversal of displacement (high-dielectric into high-conductivity) at high frequencies.

Conclusions:

The observed fluid displacement is a novel AC interfacial polarization phenomenon.
The crossover frequency for displacement reversal is governed by the electrical properties of the fluids.
Maxwell-Wagner polarization mechanics accurately explain the observed phenomenon.