Electro-osmotic flow (EOF), where ions in the electric double layer (EDL) next to the wall are driven by an electric field, is commonly used in microfluidics. Experimental observations of the velocity deficit in the EDL within 250 nm of the wall in EOF of a monovalent aqueous electrolyte solution are reported and validated by analytical predictions. Unlike other techniques for probing the EDL in quiescent solutions, this nonintrusive time-resolved technique is suitable for quantifying changes in wall potential in flowing electrolyte solutions, e.g., due to surface adsorption, in a microfluidic device.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)