Electroosmotic flow has been shown to be controlled via an applied radial voltage. Many factors determine the effectiveness of this control, and one major factor is buffer pH. In this study the effectiveness of the applied radial voltage for controlling electroosmotic flow while varying buffer pH is examined. Previously developed theory is applied and compared to experimental results for a pH r...

A characterization and optimization of the in vitro transdermal iontophoretic transport of 5-hydroxy-2-(N,N,-di-n-propylamino)tetralin (5-OH-DPAT) is presented. The utility of acetaminophen as a marker of electroosmotic flow was studied as well. The following parameters of iontophoretic transport of 5-OH-DPAT were examined: drug donor concentration, electroosmotic contribution, influence of co-...

As microfluidic technologies mature, increasingly complex solutions are employed, and accurate methods for the measurement of electroosmotic flow rates are becoming increasingly important. The methodologies of both a direct method and an indirect method of flow rate measurement are presented here. The direct method involves flow visualization using trace amounts of a caged fluorescent dye. The ...

The influence of an external electric field on the electroosmotic flow in the noncoated (bare) fused-silica capillaries and in the fused-silica capillaries with covalent coating of the inner surface by the polymer of a new acrylamido derivative, N-(acryloylaminoethoxy)ethyl-beta-D-glucopyranose, has been tested in the capillary electrophoretic separations of peptide analytes. The effect of magn...

Phase-resolved optical Doppler tomography (ODT), an imaging technique based on low coherence interferometry, is presented as a new tool to determine electroosmotic flow (EOF) in microfluidic channel. This is a non-contact technique that not only can image cross-sectional EOF profile but also can determine electroosmotic mobility. The electroosmotic coefficient measured by ODT was verified by co...

We generate and study electroosmotic shear flow in microchannels. By chemically or electrically modifying the surface potential of the channel walls a shear flow component with controllable velocity gradient can be added to the electroosmotic flow caused by double layer effects at the channel walls. Chemical modification is obtained by treating the channel wall with a cationic polymer. In case ...

a numerical study of 3d electrokinetic flows through micromixers was performed. the micromixers considered here consisted of heterogeneous rectangular microchannels with prescribed patterns of zeta-potential at their walls. numerical simulation of electroosmotic flows within heterogeneous channels requires solution of the navier-stokes, ernest-plank and species concentration equations. it is kn...

We present herein a micro reactor set-up that enables parallel syntheses to be performed under electroosmotic flow conditions.

T This paper reports the mixing performance of an AC electroosmotic micromixer based on the three-dimensional extensional flow generated by a face-to-face, asymmetric pair of planar electrodes. This work represents the first successful use of such an asymmetric electrode pair in an AC electroosmotic micromixer. Due to the highly 3dimentional flow pattern generated by the face-to-face electrode ...