Flow Restrictions and Fluid
Turbulence in Microfluidic
Channels
By Joseph M. Clift
Outline
Introduction
Gate Design and Fabrication of Gated
Channels
Fabrication of Mixers
Conclusions and Future Directions
Why is it important?
Microfluidic devices can be utilized for
a wide range of applications such as
Biosensors1,2
Microreactors1,2
Image from
http://thebigone.stanford.edu/
Fabrication of Gates
Gated channels are
produced on
Macromedia
Freehand™.
The finished drawings
are then printed on a
transparency from high
resolution laser printer
and cut to fit into the
petri dishes.
Nonlithographic
Fabrication Method
Microfluidic Gates
200mm
200mm
Image taken of three Image of 195mm microchannel at
microchannels of distances 165mm, 50x.
195mm, and 205mm at 34x.
Gate Dimensions
Microfluidic Mixers
Small cross sections and large linear
flow velocity leads to laminar flows
Mixing is essential for biosensors
(labeling of samples) and microreactors
Active mixers – moving stirrers
Passive mixers – no moving parts, the
cannel geometry generates intertwining
flows
Nonlithographic Fabrication
of Micromixers
Observations of mixing
channels
400 mm 100 mm
Conclusions
Nonlithographic fabrication is a facile and
low-cost alternatives for expedient
prototyping.
Microgate fabrication exceeded twice the
resolution of the printers we used.
Nonlithographic methods allow for the
fabrication of circular channels with
patterned walls.
Spiral grooves along the walls of
micromixers significantly increases the
mixing efficiency.
Future Directions
Evaluate fluid flow through the
microgates
Model the fluid flow in the spiral-
grooved micromixers
References
1. Trinidad National Institute of Higher Education compiler.
2001 [cited 2007 Jul 24]. Make Way for Microfluidics!
Trinidad: NIHERST. Available from:
http://www.niherst.gov.tt/scipop/sci-bits/microfluidics.htm
2. Whatis.com compiler. 2001 [cited 2007 Jul 24].
Microfluidics. Needham, MA: Whatis.com. Available from:
http://whatis.techtarget.com/definition/0,,sid9_gci526632,0
0.html
3. Stephen R. Quake compiler. 2005 [cited 2007 Aug]..
Stanford, CA: Quake Group homepage. Available from:
http://thebigone.stanford.edu/
Acknowledgements
Dr. Vullev BRITE
Marlon Thomas administration and
Connie Chong members
Brent Millare
Amy Ferriera
Elizabeth Zielins