Quantification of electrical field-induced flow reversal in a microchannel.
We characterize the electroosmotic flow in a microchannel with field effect flow control. High resolution measurements of the flow velocity, performed by micro particle image velocimetry, evidence the flow reversal induced by a local modification of the surface charge due to the presence of the gate. The shape of the microchannel cross-section is accurately extracted from these measurements. Experimental velocity profiles show a quantitative agreement with numerical results accounting for this exact shape. Analytical predictions assuming a rectangular cross-section are found to give a reasonable estimate of the velocity far enough from the walls.
Pirat
C
C
Physics of Fluids Group, Department of Applied Physics, University of Twente, P.O. Box 217, 7500 AE, Enschede, The Netherlands.
Naso
A
A
van der Wouden
E J
EJ
Gardeniers
J G E
JG
Lohse
D
D
van den Berg
A
A
D004574:Electromagnetic Fields; D053841:Electroosmosis / Q000295:instrumentation / Q000379:methods*; D004867:Equipment Design; D015640:Ion Channel Gating / Q000502:physiology*; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D012212:Rheology / Q000295:instrumentation / Q000379:methods*