Even though microfluidic devices are slowly becoming commercial reality (e.g. Inkjet printers), the challenges in the design of microfluidic devices remain since not all aspects of fluid flow in microchannels have been fully understood yet. This paper presents an extensive review of studies on flow physics for both pressure-driven and electrokinetic flows in microchannels. The primary goal of the present paper is to provide a wide overview of findings on underlying principles of microflow physics. The issues discussed include the effect of pressure drop and friction measurements; mixing and flow control methods for microfluidic systems; and joule heating and viscous dissipation effects in microchannel flows. No agreement has been found among studies focusing on the characterization of friction factor/pressure drop for microflow systems. Further investigation requires understanding how entrance effects differ in the case of microflows when compared to macro scale flow. There is a clear need to investigate characteristics of non-Newtonian fluid flow in microchannels.

1.
Barker
S. L. R.
,
Ross
D.
,
Tarlov
M. J.
,
Gaitan
M.
, and
Locascio
L. E.
, (
2000
) “
Control of Flow Direction in Microfluidic Devices with Polyelectrolyte Multilayers
,”
Anal. Chem.
, Vol.
72
, pp.
5925
5929
.
2.
Chen
C.-H.
,
Santiago
G.
(
2002
) “
A planar electroosmotic micropump
,”
Journal of Microelectromechanical Systems
, Vol.
11
, No.
6
, pp.
672
683
.
3.
Conlisk
A. T.
,
McFerran
J.
,
Zheng
Z.
, and
Hansford
D.
(
2002
) “
Mass transfer and flow in electrically charged micro- and nanochannels
,”
Anal. Chem.
, Vol.
74
, pp.
2139
2150
.
4.
Devasenathipathy, S. and Santiago, J.G. (2003) “Electrokinetic Flow Diagnostics,” Micro- and Nano-Scale Diagnostic Techniques, Section 3, Ed. K.S. Breuer, Springer Verlag, New York.
5.
Ducree, J., Brenner, T., Glatzel, T., and Zengerle, R., (2003) “Coriolis-Induced Switching and Mixing of Laminar Flows in Rotating Microchannels,” accepted for Proceeding of Micro. tec 2003; pp. 397–404.
6.
Goettsche, T., Kohnle, J., Willmann, M., Ernst, H., Messner, S., Steger, R., Storz, M., Lang, W., Zengerle, R., and Sandmaier, H., (2003) “Novel Approaches to Microfluidic Components in High-End Medical Applications,” The 12th International Conference on Solid State Sensors, Actuators and Microsystems.
7.
Hasselbrink
E. F.
,
Shepodd
T. J.
, and
Rehm
J. E.
, (
2002
) “
High-Pressure Microfluidic Control in Lab-on-a-Chip Devices Using Mobile Polymer Monoliths
,”
Anal. Chem.
, Vol.
74
, pp.
4913
4918
.
8.
Hetsroni
G.
,
Mosyak
A.
,
Pogrebnyak
E.
,
Yarin
L. P.
(
2005
) “
Fluid flow in micro-channels
,”
International Journal of Heat and Mass Transfer
, Vol.
48
, pp.
1982
1998
.
9.
He
B.
,
Burke
B. J.
,
Zhang
X.
,
Zhang
R.
and
Regnier
Fred E.
, (
2001
) “
A Picoliter-Volume Mixer for Microfluidic Analytical Systems
,”
Anal. Chem.
, Vol.
73
, pp.
1942
1947
.
10.
Horiuchi
K.
,
Dutta
P.
, (
2004
) “
Joule heating effects in electroosmotically driven microchannel flows
,”
International Journal of Heat and Mass Transfer
, Vol.
47
, pp.
3085
3095
.
11.
Ismagilov
R. F.
,
Rosmarin
D.
,
Kenis
P. J. A.
,
Chiu
D. T.
,
Zhang
W.
,
Stone
H. A.
, and
Whitesides
G. M.
, (
2001
) “
Pressure-Driven Laminar Flow in Tangential Microchannels: an Elastomeric Microfluidic Switch
,”
Anal. Chem.
, Vol.
73
, pp.
4682
4687
.
12.
Judy
J.
,
Maynes
D.
,
Webb
B. W.
, (
2002
) “
Characterization of frictional pressure drop for liquid flows through microchannels
,”
International Journal of Heat and Mass Transfer
, Vol.
45
, pp.
3477
3489
.
13.
Kohl
M. J.
,
Abdel-Khalik
S. I.
,
Jeter
S. M.
,
Sadowski
D. L.
(
2005
) “
An experimental investigation of microchannel flow with internal pressure measurements
,”
International Journal of Heat and Mass Transfer
, Vol.
48
, pp.
1518
1533
.
14.
Koo
J.
and
Kleinstreuer
C.
, (
2003
) “
Liquid flow in microchannels: experimental observations and computational analyses of microfluidics effects
,”
Journal of Micromechanics and Microengineering
, Vol.
13
, pp.
568
579
15.
Koo
J.
and
Kleinstreuer
C.
(
2004
) “
Viscous dissipation effects in microtubes and microchannels
,”
International Journal of Heat and Mass Transfer
, Vol.
47
, pp.
3159
3169
.
16.
Lee, Y-K., Deval, J., Tabeling, P., and Ho, C-H. (2001) “Chaotic Mixing in Electrokinetically and Pressure Driven Micro Flows,” The 14th IEEE Workshop on MEMS Interlaken, Switzerland.
17.
Lim
D. S. W.
,
Kuo
J. S.
,
Chiu
D. T.
(
2004
) “
Parametric investigation on the effect of channel topologies on electrophoretic separations
,”
Journal of Chromatography A
, Vol.
1027
, pp.
237
244
.
18.
Liu
R. H.
,
Stremler
M. A.
,
Sharp
K. V.
,
Oslen
M. G.
,
Santiago
J. G.
,
Adrian
R. J.
,
Aref
H.
, and
Beebe
D. J.
, (
2000
) “
Passive Mixing in a Three-Dimensional Serpentine Microchannel
,”
Journal of Microelectromechanical Systems
, Vol.
9
, No.
2
, pp.
190
197
.
19.
Mala
G. M.
, and
Li
D.
, (
1999
) “
Flow characteristics of water in Microtubes
,”
Int. J. Heat Mass Transfer
, Vol.
20
142
148
.
20.
Maynes
D.
,
Webb
B. W.
(
2004
) “
The effect of viscous dissipation in thermally fully-developed electro-osmotic heat transfer in microchannels
,”
International Journal of Heat and Mass Transfer
, Vol.
47
, pp.
987
999
.
21.
Papautsky, I., Gale, B. K., Mohanty, S., Ameel, T. A., and Frazier, A. B., (1999) “Effects of rectangular microchannel aspect ratio on laminar friction constant,” Proceedings of SPIE - The International Society for Optical Engineering Proceedings of the 1999 Microfluidic Devices and Systems II, Vol. 3877, pp. 147–158.
22.
Peng
X. F.
, and
Peterson
G. P.
, (
1996
) “
Convective heat transfer and flow friction for water flow in microchannel structures
,”
Int. J. Heat and Mass Transfer
, Vol.
39
, pp.
2599
2608
.
23.
Peng
X. F.
,
Peterson
G. P.
, and
Wang
B. X.
, (
1994
) “
Frictional flow characteristics of water flowing through rectangular microchannels
,”
Exp. Heat Transfer
, Vol.
7
,
249
264
.
24.
Polson
N.
, and
Hayes
M, A.
, (
2000
) “
Electroosmotic Flow Control of Fluids on a Capillary Electrophoresis Microdevice Using an Applied External Voltage
,”
Anal. Chem.
, Vol.
72
, pp.
1088
1092
.
25.
Ren
L.
,
Qu
W.
, and
Li
D.
, (
2001
) “
Interfacial electrokinetic effects on liquid flow in microchannels
,”
International Journal of Heat and Mass Transfer
, Vol.
44
, pp.
3125
3134
.
26.
Sinton
D.
,
Escobedo-Canseco
C.
,
Ren
L.
, and
Li
D.
(
2002
) “
Direct and indirect electroosmotic flow velocity measurements in microchannels
,”
Journal of Colloid and Interface Science
, Vol.
254
, pp.
1
6
.
27.
Stroock
A. D.
,
Dertinger
S. K
,
Whitesides
G. M.
, and
Ajdari
A
(
2003
) “
Patterning Flows Using Grooved Surfaces
,”
Anal. Chem.
Vol.
74
, pp.
5306
5312
.
28.
Stroock
A. D.
, and
Whitesides
G. M.
, (
2003
) “
Controlling Flows in Microchannels with Patterned Surface Charge and Topography
,”
Acc. Chem. Res.
Vol.
36
, pp.
597
604
.
29.
Sui
Z.
, and
Schlenoff
J. B.
, (
2003
) “
Controlling Electroosmotic Flow in Microchannels with pH-Responsive Polyelectrolyte Multilayers
,”
Langmuir
, Vol.
19
, pp.
7829
7831
.
30.
Swinney
K.
and
Bornhop
D. J.
(
2002
) “
Quantification and evaluation of Joule heating in on-chip capillary electrophoresis
,”
Electrophoresis
, Vol.
23
, pp.
613
620
.
31.
Takuto, A., Soo, K. M., Hiroshi, I., and Kenjiro, S., (2000) “An Experimental Investigation of Gaseous Flow Characteristics in Microchannels,” Proceedings of the International Conference on Heat Transfer and Transport Phenomena in Microscale, pp. 155–161.
32.
Tang
G. Y.
,
Yang
C.
,
Chai
C. K.
,
Gong
H. Q.
(
2004
) “
Numerical analysis of the thermal effect on electroosmotic flow
,”
Analytica Chimica Acta
, Vol.
507
, pp.
27
37
.
33.
Wu
H. Y.
, and
Cheng
P.
, (
2003
) “
Friction Factors in Smooth Trapezoidal Silicon Microchannels with Different Aspect Ratios
,”
International Journal of Heat and Mass Transfer
, Vol.
46
, pp.
2519
2525
.
34.
Wu
P.
, and
Little
W. A.
, (
1983
) “
Measurement of friction factors for the flow of gases in very fine channels used for microminiature Joule-Thomson refrigerators
,
Cryogenics
, Vol.
23
pp.
273
277
.
35.
Xu
B.
,
Ooi
K. T.
,
Wong
N. T.
, (
2000
) “
Experimental investigation of flow friction for liquid flow in microchannels
,”
Int. Commun. Heat Mass Transfer
, Vol.
27
, No.
8
, pp.
1165
1176
.
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