changes of hydrodynamic parameters in microchannel branches affect the suspended biological samples in blood. to prevent denaturation and hemolysis, we have numerically investigated the effect of divergence angle on shear rate and velocity at branch entrance (discharge rate), under electroosmotic flow. in such flow, hydrodynamic properties are also affected by zeta potential at the microchannel...

We demonstrate a technique for the precise immobilization of nanoscale objects at accurate positions on two-dimensional surfaces. We have developed a water-based photoresist that causes nanostructures such as colloidal quantum dots to segregate to a thin layer at surfaces. By combining this material with electroosmotic feedback control, we demonstrate the ability to position selected, individua...

Three alkali cations, potassium, sodium, and lithium, have been separated within 15 s in a 1 cm long polymer microchip. The separation microchannel is modified by a polycation, poly(allylammonium chloride), which makes the channel surfaces positively charged leading to a reversed electroosmotic flow (EOF) when compared to bare channels. Due to the decreased apparent mobility of the cations, the...

Accurate permeability estimation has always been a concern in determining flow units, assigning appropriate capillary pressure andrelative permeability curves to reservoir rock types, geological modeling, and dynamic simulation.Acoustic method can be used as analternative and effective tool for permeability determination. In this study, a four-step approach is proposed for permeability estimati...

We developed a numerical code which allows fast and accurate simulation of isotachophoresis (ITP). The multi-species code accounts for equilibrium chemistry, non-uniform electroosmotic flow, and dispersion. Our modeling efforts for the latter are also presented. The goal of our work is to create an efficient, accurate, validated, and uniquely-capable electrophoresis simulation code available fo...

reservoir permeability is a critical parameter for characterization of the hydrocarbon reservoirs. in fact, determination of permeability is a crucial task in reserve estimation, production and development. traditional methods for permeability prediction are well log and core data analysis which are very expensive and time-consuming. well log data is an alternative approach for prediction of pe...

Using an applied electrical field to drive fluid flows becomes desirable as channels become smaller. Although most discussions of electroosmosis treat the case of thin Debye layers, here electroosmotic flow (EOF) through a constricted cylinder is presented for arbitrary Debye lengths (kappa(-1)) using a long wavelength perturbation of the cylinder radius. The analysis uses the approximation of ...

In this paper, we describe an amperometric-type enzymeless glucose sensing system based on a nanoporous platinum (Pt) electrode embedded in a microfluidic chip. This microchip system is comprised of a microfluidic transport channel network and a miniaturized electrochemical cell for nonenzymatic glucose sensing. Sample and buffer solutions were transferred to the cell by programmed electroosmot...