Electroosmotic Flows of Power-Law Fluids with Asymmetric Electrochemical Boundary Conditions in a Rectangular Microchannel

Wooseok Choi,Sungchan Yun,Du-Soon Choi

doi:10.3390/mi8050165

Wooseok Choi, Sungchan Yun + Show 1 more

Open Access

https://doi.org/10.3390/mi8050165

Copy DOI

Journal: Micromachines	Publication Date: May 20, 2017
Citations: 6	License type: CC BY 4.0

Affiliation: Korea National University of Transportation

Abstract

In this paper, a systematic study of a fully developed electroosmotic flow of power-law fluids in a rectangular microchannel bounded by walls with different zeta potentials is described. Because the upper and lower layers of most microchannels are made of different materials, it is necessary to study the flow characteristics for cases in which the microchannels have different zeta potentials at each wall. The electrical potential and momentum equations were solved numerically using a finite element analysis. The velocity profiles and flow rates were studied parametrically by varying the fluid behavior index, channel aspect ratio, and electrochemical properties of the liquid and the bounding walls. The calculated volumetric flow rates in a rectangular microchannel were compared with those between two infinite parallel plates.

Highlights

Electroosmotic flow (EOF) is one of the most important techniques in a microfluidic system because conventional pressure-driven flows are inefficient owing to a high surface-to-volume ratio at the microscale
Most studies on EOFs have assumed that the medium in the microchannel is a Newtonian fluid, which is a rational consideration because most electrolytes or buffer solutions used in microfluidic devices are Newtonian
Among the various models for non-Newtonian fluids, the power-law model has been the most chosen rheological model for EOFs occurring in a microchannel, owing to its simplicity and adequateness in terms of the flow behavior [13,14]

Summary

Introduction

Electroosmotic flow (EOF) is one of the most important techniques in a microfluidic system because conventional pressure-driven flows are inefficient owing to a high surface-to-volume ratio at the microscale. Among the various models for non-Newtonian fluids, the power-law model has been the most chosen rheological model for EOFs occurring in a microchannel, owing to its simplicity and adequateness in terms of the flow behavior [13,14].

Results

Conclusion