banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Direction dependence of displacement time for two-fluid electroosmotic flow
Rent this article for


Image of FIG. 1.
FIG. 1.

Schematic diagram of experimental setup for current monitoring method.

Image of FIG. 2.
FIG. 2.

Current-time curve for displacement flow of 0.2 mM and 1 mM KCl solutions in glass micro-capillary.

Image of FIG. 3.
FIG. 3.

Displacement time for 1 mM KCl with (a) 0.2 mM, (b) 0.5 mM, (c) 0.7 mM, and (d) 0.95 mM KCl for flows in both directions in glass micro-capillary with diameter of 100 μm and length of 8 cm under applied voltage of 1000 V. Error bars indicate the standard deviations.

Image of FIG. 4.
FIG. 4.

Percentage time difference between displacement time in both directions for KCl solution with various percentage of concentration differences at various (a) voltages (with micro-capillary length of 8 cm and diameter of 100 μm), (b) micro-capillary diameters (length was fixed at 8 cm), and (c) micro-capillary lengths (diameter was fixed at 100 μm).

Image of FIG. 5.
FIG. 5.

(a) Displacement time in PDMS microchannel with KCl solutions of various percentage concentration differences under applied voltage of 330 V over channel length of 5.5 cm and (b) comparison between percentage time difference for PDMS channel and glass micro-capillary (6 cm) at various concentration differences.

Image of FIG. 6.
FIG. 6.

Simulation domain and coordinate system for axisymmetric analysis.

Image of FIG. 7.
FIG. 7.

Flowchart of numerical solving process.

Image of FIG. 8.
FIG. 8.

Numerical results showing (a) flow rate and (b) displacement of fluid interface in the displacement flow of 0.01 mM and 0.002 mM solutions. Single fluid flows for each of the two solutions are shown for reference.

Image of FIG. 9.
FIG. 9.

Comparison between experimental and numerical results for displacement flow of two solutions with 80% concentration difference. Currents are normalized with maximum and minimum currents. Time is normalized with the time for the descending curve to reach a steady current.

Image of FIG. 10.
FIG. 10.

Positive and negative ion distributions x = 0.8 × 10−4 m for the flow of (a) 0.002 mM displacing 0.01 mM and (b) 0.01 mM displacing 0.002 mM. Full curves represent negative ion and dashed curves represent positive ion.

Image of FIG. 11.
FIG. 11.

Snapshots of velocity vector plot for flow of (a) 0.002 mM displacing 0.01 mM and (b) 0.01 mM displacing 0.002 mM. Numerical results show that velocity profiles in two fluid displacement flow deviate from the plug-like profile of a typical electroosmotic flow.

Image of FIG. 12.
FIG. 12.

Comparison of negative ion distributions between both flow directions at bulk concentration of 0.004 mM, 0.006 mM and 0.008 mM at x = 0.8 × 10−4 m. Full curves represent the case of high concentration displacing low concentration and dashed curves represent the case of low concentration displacing high concentration.


Generic image for table
Table I.

t-score for displacement time of various solutions pairs at 3 voltages applied in glass micro-capillary.

Generic image for table
Table II.

Symbols and values of parameters in numerical models.

Generic image for table
Table III.

Summary of boundary conditions for steady state numerical model for single fluid electroosmotic flow.

Generic image for table
Table IV.

Changes in inlet boundary conditions for two-fluid displacement flow (R= concentration ratio between two solutions).


Article metrics loading...


Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Direction dependence of displacement time for two-fluid electroosmotic flow