Flow Reversal in Traveling-Wave Electrokinetics: An Analysis of Forces Due to Ionic Concentration Gradients


Garcia-Sanchez, Pablo, Ramos, Antonio, Gonzalez, Antonio, Green, Nicolas G and Morgan, Hywel (2009) Flow Reversal in Traveling-Wave Electrokinetics: An Analysis of Forces Due to Ionic Concentration Gradients. LANGMUIR, 25, (9), 4988-4997.

Download

[img] PDF
Restricted to Registered users only

Download (952Kb) | Request a copy

Description/Abstract

Pumping of electrolytes using ac electric fields from arrays of microelectrodes is a subject of current research. The behavior of fluids at low signal amplitudes (< 2-3 V-pp) is in qualitative agreement with the prediction of the ac electroosmosis theory. At higher voltages, this theory cannot account for the experimental observations. In some cases, net pumping is generated in the direction opposite to that predicted by the theory (flow reversal). In this work, we use fluorescent dyes to study the effect of ionic concentration gradients generated by Faradaic currents. We also evaluate the influence of factors such as the channel height and microelectrode array shape in the pumping of electrolytes with traveling-wave potentials. Induced charge beyond the Debye length is postulated to be responsible for the forces generating the observed flows at higher voltages. Numerical calculations are performed in order to illustrate the mechanisms that might be responsible for generating the flow.

Item Type: Article
Additional Information: Imported from ISI Web of Science
Divisions: Faculty of Physical Sciences and Engineering > Electronics and Computer Science > NANO
ePrint ID: 270024
Date Deposited: 21 Apr 2010 07:46
Last Modified: 27 Mar 2014 20:15
Further Information:Google Scholar
ISI Citation Count:8
URI: http://eprints.soton.ac.uk/id/eprint/270024

Actions (login required)

View Item View Item

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics