Electrokinetic transport in microchannels with random roughness
Journal Article
·
· Analytical Chemistry
OSTI ID:956651
- Los Alamos National Laboratory
We present a numerical framework to model the electrokinetic transport in microchannels with random roughness. The three-dimensional microstructure of the rough channel is generated by a random generation-growth method with three statistical parameters to control the number density, the total volume fraction, and the anisotropy characteristics of roughness elements. The governing equations for the electrokinetic transport are solved by a high-efficiency lattice Poisson?Boltzmann method in complex geometries. The effects from the geometric characteristics of roughness on the electrokinetic transport in microchannels are therefore modeled and analyzed. For a given total roughness volume fraction, a higher number density leads to a lower fluctuation because of the random factors. The electroosmotic flow rate increases with the roughness number density nearly logarithmically for a given volume fraction of roughness but decreases with the volume fraction for a given roughness number density. When both the volume fraction and the number density of roughness are given, the electroosmotic flow rate is enhanced by the increase of the characteristic length along the external electric field direction but is reduced by that in the direction across the channel. For a given microstructure of the rough microchannel, the electroosmotic flow rate decreases with the Debye length. It is found that the shape resistance of roughness is responsible for the flow rate reduction in the rough channel compared to the smooth channel even for very thin double layers, and hence plays an important role in microchannel electroosmotic flows.
- Research Organization:
- Los Alamos National Laboratory (LANL)
- Sponsoring Organization:
- DOE
- DOE Contract Number:
- AC52-06NA25396
- OSTI ID:
- 956651
- Report Number(s):
- LA-UR-08-07925; LA-UR-08-7925
- Journal Information:
- Analytical Chemistry, Journal Name: Analytical Chemistry Journal Issue: 8 Vol. 81
- Country of Publication:
- United States
- Language:
- English
Similar Records
Electrokinetic pump
Molecular dynamics and continuum analyses of the electrokinetic zeta potential in nanostructured slit channels
Apparatus for producing a thin sample band in a microchannel system
Patent
·
Tue Aug 03 00:00:00 EDT 2004
·
OSTI ID:1174968
Molecular dynamics and continuum analyses of the electrokinetic zeta potential in nanostructured slit channels
Journal Article
·
Wed Jun 24 20:00:00 EDT 2020
· Colloids and Surfaces. A, Physicochemical and Engineering Aspects
·
OSTI ID:1851746
Apparatus for producing a thin sample band in a microchannel system
Patent
·
Tue May 13 00:00:00 EDT 2008
·
OSTI ID:936330