Electrokinetically-driven flow circulations resulting from heterogeneous surface patches have previously been employed to improve mixing in microchannels. Here, numerical simulations demonstrate local in-channel hydrodynamic focusing through the use of strategically-patterned surface charge. Presented first is the case of a single straight channel with an axially-localized cross-sectional surface patch (ring). The surface patch exhibits a zeta potential equal in magnitude to the native microchannel surface but opposite in sign. The unsteady species transport in the presence of the electrokinetically-induced circulations is modelled, and a mean residence time is quantified. In general, residence times indicate the potential application of these circulations to microfluidic-based memory storage. Next, an improved focusing process for pinched-injection is demonstrated that exploits non-uniform surface patches. Lastly, surface patches are applied to enhance stream focusing in the microfluidic cross geometry. It is demonstrated that with this technique three-dimensional hydrodynamic focusing can be achieved in a single planar microfluidic structure. In one case, the microfluidic fluid stream was constrained to the centre of the channel and focused to 12% of its original cross-sectional area. Extensions of this work are discussed, as are the microfabrication and surface modification processes required for lab-on-chip implementation of these numerically simulated processes.
Skip Nav Destination
ASME 3rd International Conference on Microchannels and Minichannels
June 13–15, 2005
Toronto, Ontario, Canada
Conference Sponsors:
- Nanotechnology Institute
ISBN:
0-7918-4185-5
PROCEEDINGS PAPER
Three-Dimensional Microfluidic Focusing With Surface Charge Patterning
Jeffrey T. Coleman,
Jeffrey T. Coleman
University of Victoria, Victoria, BC, Canada
Search for other works by this author on:
David Sinton
David Sinton
University of Victoria, Victoria, BC, Canada
Search for other works by this author on:
Jeffrey T. Coleman
University of Victoria, Victoria, BC, Canada
David Sinton
University of Victoria, Victoria, BC, Canada
Paper No:
ICMM2005-75235, pp. 599-603; 5 pages
Published Online:
November 11, 2008
Citation
Coleman, JT, & Sinton, D. "Three-Dimensional Microfluidic Focusing With Surface Charge Patterning." Proceedings of the ASME 3rd International Conference on Microchannels and Minichannels. ASME 3rd International Conference on Microchannels and Minichannels, Part B cont’d. Toronto, Ontario, Canada. June 13–15, 2005. pp. 599-603. ASME. https://doi.org/10.1115/ICMM2005-75235
Download citation file:
3
Views
Related Proceedings Papers
Related Articles
A Microfluidic Device to Establish Concentration Gradients Using Reagent Density Differences
J Biomech Eng (December,2010)
Microfluidic Transport in Ternary Liquid Layers Due to Sinusoidal Thermocapillary Actuation
J. Heat Mass Transfer (July,2023)
Analysis of Droplet Generation in Electrospray Using a Carbon Fiber Based Microfluidic Emitter
J. Fluids Eng (July,2011)
Related Chapters
Completing the Picture
Air Engines: The History, Science, and Reality of the Perfect Engine
Introduction
Design of Mechanical Bearings in Cardiac Assist Devices
Hydrodynamic Lubrication
Design of Mechanical Bearings in Cardiac Assist Devices