A novel passive micromixer, denoted as the Y-Y mixer, based on split-and-recombine (SAR) principle is proposed and studied both experimentally and numerically over Reynolds numbers ranging from 1 to 100. Two species are supplied to a prototype via a Y inlet, and flow through four identical elements repeated in series; the width of the mixing channel varies from 0.4 to 0.6 mm, while depth is 0.4 mm. An image analysis technique was used to evaluate mixture homogeneity at four target areas along the mixer. Numerical simulations were found to be a useful support for observing the complex three-dimensional flow inside the channels. Comparison with a known mixer, the tear-drop one, based on the same SAR principle, was also performed, to have a point of reference for evaluating performances. A good agreement was found between numerical and experimental results. Over the examined range of Reynolds numbers Re, the Y-Y micromixer showed at its exit an almost flat mixing characteristic, with a mixing efficiency higher than 0.9; conversely, the tear-drop mixer showed a relevant decrease of efficiency at the midrange. The good performance of the Y-Y micromixer is due to the three-dimensional 90 deg change of direction that occurs in its channel geometry, which causes a fluid swirling already at the midrange of Reynolds numbers. Consequently, the fluid path is lengthened and the interfacial area of species is increased, compensating for the residence time reduction.

References

References
1.
Kane
,
A. S.
,
Hoffmann
,
A.
,
Baumgärtel
,
P.
,
Seckler
,
R.
,
Reichardt
,
G.
,
Horsley
,
D. A.
,
Schuler
,
B.
, and
Bakajin
,
O.
,
2008
, “
Microfluidic Mixers for the Investigation of Rapid Protein Folding Kinetics Using Synchrotron Radiation Circular Dichroism Spectroscopy
,”
Anal. Chem.
,
80
(
24
), pp.
9534
9541
.
2.
Jang
,
A.
,
Zou
,
Z.
,
Lee
,
K. K.
,
Ahn
,
C. H.
, and
Bishop
,
P. L.
,
2011
, “
State-of-the-Art Lab Chip Sensors for Environmental Water Monitoring
,”
Meas. Sci. Technol.
,
22
(3), pp.
1
18
.
3.
Nguyen
,
N. T.
, and
Wu
,
Z.
,
2005
, “
Micromixers: A Review
,”
J. Micromech. Microeng.
,
15
(
2
), pp.
R1
R16
.
4.
Capretto
,
L.
,
Cheng
,
W.
,
Hil
,
M.
, and
Zhang
,
X.
,
2011
, “
Micromixing Within Microfluidic Devices
,”
Top. Curr. Chem.
,
304
(2), pp.
27
68
.
5.
Hessel
,
V.
,
Löwe
,
H.
, and
Schönfeld
,
F.
,
2005
, “
Micromixers—A Review on Passive and Active Mixing Principles
,”
Chem. Eng. Sci.
,
60
(8–9), pp.
2479
2501
.
6.
Ammar
,
H.
,
El Moctar
,
A. O.
,
Garnier
,
B.
, and
Peerhossaini
,
H.
,
2014
, “
Flow Pulsation and Geometry Effects on Mixing of Two Miscible Fluids in Microchannels
,”
ASME J. Fluids Eng.
,
136
(
12
), p.
121101
.
7.
Kamholz
,
A. E.
,
Weigl
,
B. H.
,
Finlayson
,
B. A.
, and
Yager
,
P.
,
1999
, “
Quantitative Analysis of Molecular Interactive in Microfluidic Channel: The T-sensor
,”
Anal. Chem.
,
71
(
23
), pp.
5340
7347
.
8.
Ismagilov
,
R. F.
,
Stroock
,
A. D.
,
Kenis
,
P. J. A.
,
Whitesides
,
G.
, and
Stone
,
H. A.
,
2000
, “
Experimental and Theoretical Scaling Laws for Transverse Diffusive Broadening in Two-Phase Laminar Flows in Microchannel
,”
Appl. Phys. Lett.
,
76
(
17
), pp.
2376
2378
.
9.
Wong
,
S. H.
,
Ward
,
M. C. L.
, and
Wharton
,
C. W.
,
2004
, “
Micro T-Mixer as a Rapid Mixing Micromixer
,”
Sens. Actuators B
,
100
(
3
), pp.
359
379
.
10.
Cha
,
J.
,
Kim
,
J.
,
Ryu
,
S.
,
Park
,
J.
,
Jeong
,
Y.
,
Park
,
S.
,
Kim
,
H.
, and
Chun
,
K.
,
2006
, “
A Highly Efficient 3D Micromixer Using Soft PDMS Bonding
,”
J. Micromech. Microeng.
,
16
(
9
), pp.
1778
1782
.
11.
Knight
,
J.
,
Vishwanath
,
A.
,
Brody
,
J.
, and
Austin
,
R.
,
1998
, “
Hydrodynamic Focusing on a Silicon Chip: Mixing Nanoliters in Microseconds
,”
Phys. Rev. Lett.
,
80
(
17
), pp.
3863
3866
.
12.
Stroock
,
A. D.
,
Dertinger
,
S. K. W.
,
Ajdari
,
A.
,
Mezić
,
I.
,
Stone
,
H. A.
, and
Whitesides
,
G. M.
,
2002
, “
Chaotic Mixer for Microchannels
,”
Science
,
295
(
5555
), pp.
647
651
.
13.
Nguyen
,
T. N. T.
,
Kimb
,
M. C.
,
Park
,
J.-S.
, and
Lee
,
N.-E.
,
2008
, “
An Effective Passive Microfluidic Mixer Utilizing Chaotic Advection
,”
Sens. Actuators B
,
132
(
1
), pp.
172
181
.
14.
Tsui
,
Y.-Y.
,
Yang
,
C.-S.
, and
Hsieh
,
C.-M.
,
2008
, “
Evaluation of the Mixing Performance of the Micromixers With Grooved or Obstructed Channels
,”
ASME J. Fluids Eng.
,
130
(
7
), p.
071102
.
15.
Cook
,
K. J.
,
Fan
,
Y.
, and
Hassan
,
I.
,
2013
, “
Mixing Evaluation of a Passive Scaled-Up Serpentine Micromixer With Slanted Grooves
,”
ASME J. Fluids Eng.
,
135
(
8
), p.
081102
.
16.
Zhou
,
T.
,
Xu
,
Y.
,
Liu
,
Z.
, and
Joo
,
S. W.
,
2015
, “
An Enhanced One-Layer Passive Microfluidic Mixer With an Optimized Lateral Structure With the Dean Effect
,”
ASME J. Fluids Eng.
,
137
(
9
), p.
091102
.
17.
Bertsch
,
A.
,
Heimgartner
,
S.
,
Cousseau
,
P.
, and
Renaud
,
P.
,
2001
, “
Static Micromixers Based on Large-Scale Industrial Mixer Geometry
,”
Lab Chip
,
1
(
1
), pp.
56
60
.
18.
Ohkawa
,
K.
,
Nakamotob
,
T.
,
Izuka
,
Y.
,
Hirata
,
Y.
, and
Inoue
,
Y.
,
2008
, “
Flow and Mixing Characteristics of σ-Type Plate Static Mixer With Splitting and Inverse Recombination
,”
Chem. Eng. Res. Des.
,
86
(
12
), pp.
1447
1453
.
19.
Chen
,
Z.
,
Bown
,
M. R.
,
Sullivan
,
B. O.
,
MacInnes
,
J. M.
,
Allen
,
R. W. K.
,
Mulder
,
M.
,
Blom
,
M.
, and
Oever
,
R. V.
,
2009
, “
Performance Analysis of a Folding Flow Micromixer
,”
Microfluid. Nanofluid.
,
6
(
6
), pp.
763
774
.
20.
Viktorov
,
V.
, and
Nimafar
,
M.
,
2013
, “
A Novel Generation of 3D SAR-Based Passive Micromixer: Efficient Mixing and Low Pressure Drop at a Low Reynolds Number
,”
J. Micromech. Microeng.
,
23
(5), pp.
1
13
.
21.
Nimafar
,
M.
,
Viktorov
,
V.
, and
Martinelli
,
M.
,
2012
, “
Experimental Investigation of Split and Recombination Micromixer in Confront With Basic T and O-Type Micromixers
,”
Int. J. Mech. Appl.
,
2
(5), pp.
61
69
.
22.
Nimafar
,
M.
,
Viktorov
,
V.
, and
Martinelli
,
M.
,
2012
, “
Experimental Comparative Mixing Performance of Passive Micromixers With H-Shaped Sub-Channels
,”
Chem. Eng. Sci.
,
76
, pp.
37
44
.
23.
Ansari
,
M. A.
,
Kim
,
K.-Y.
, and
Kim
,
S. M.
,
2010
, “
Numerical Study of the Effect on Mixing of the Position of Fluid Stream Interfaces in a Rectangular Microchannel
,”
Microsyst. Technol.
,
16
(
10
), pp.
1757
1763
.
24.
Engler
,
M.
,
Kockmann
,
N.
,
Kiefer
,
T.
, and
Woias
,
P.
,
2004
, “
Numerical and Experimental Investigations on Liquid Mixing in Static Micromixers
,”
Chem. Eng. J.
,
101
(1–3), pp.
315
322
.
25.
Nguyen
,
N. T.
,
2008
,
Micromixers Fundamentals, Design and Fabrication
,
William Andrew
,
Norwich, NY
.
26.
Amini
,
H.
,
Sollier
,
E.
,
Masaeli
,
M.
,
Xie
,
Y.
,
Ganapathysubramanian
,
B.
,
Stone
,
H. A.
, and
Di Carlo
,
D.
,
2013
, “
Engineering Fluid Flow Using Sequenced Microstructures
,”
Nat. Commun.
,
4
, p.
1826
.
27.
Liao
,
Y.
,
Song
,
J.
,
Li
,
E.
,
Luo
,
Y.
,
Shen
,
Y.
,
Chen
,
D.
,
Cheng
,
Y.
,
Xu
,
Z.
,
Sugioka
,
K.
, and
Midorikawa
,
K.
,
2012
, “
Rapid Prototyping of Three-Dimensional Microfluidic Mixers in Glass by Femtosecond Laser Direct Writing
,”
Lab Chip
,
12
(
4
), pp.
746
749
.
You do not currently have access to this content.