Introduction of Micro-mixer
Lab on a chip
Mixing principles
Micro-scale
Micro-scale
=> laminar flow conditions
=> difficult to mix
Modes of Mixing
Split and recombine Serial segmentation Rotation Chaotic vortex Supply external energy
Thermal
Acoustic
Electro-somotic
Mechanical
Passive
Active
Mixing by diffusion
Diffusive micro mixer - and gradient generator
Whitesides G. et al, Langmuir, Vol. 16, No. 22, 2000, 8311-8316
Laminated flow cell scanner
Orwar O. et al Anal. Chem. 2002, 74, 6133-6138
Laminated flow cell scanner- and decade gradient generator
Orwar O. Et al Anal. Chem. 2005, 77, 3897-3903
Distributive micromixing chip
Chaotic advection micro mixers- 3D rotation of the laminated flows
Nuguyen N-T., Fundamentals and applications of microfluidics
Chaotic advection serpentine mixer -3D rotation of the laminated flows -
BEEBE D. et al. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 9, NO. 2, JUNE 2000
Chaotic advection in serpentine mixer
Chaotic advection mixing -grooved channel bottom-
G.M. Whitesides et al SCIENCE VOL 295 25 JANUARY 2002 647
Chaotic advection mixing -patterned channel bottom-
Nuguyen N-T., Fundamentals and applications of microfluidics
Chaotic advection mixing- periodic herring bone pattern -
G.M. Whitesides et al SCIENCE VOL 295 25 JANUARY 2002 647
Chaotic advection mixing -periodic herring bone pattern-
Dispersion properties of herringbone mixer
Straight
Herringbone
G.M. Whitesides et al Science Vol 295 25 Jan. 2002 647
Serially segmented chaotic mixer
P. Tableing et al Physical Review E 72, 056312, 2005
Multilamination mixing
Jensen K F. et al, Ind. Eng. Chem. Res., Vol. 44, No. 8, 2005
Multilamination mixingand alkaline hydrolysis of methyl formate
Multiphase mixing
Semented flow mixing - gas/fluid -
Jensen KF. et al Langmuir, Vol. 21, No. 4, 2005
Re-Pe diagram
Pe - inertia (advection) in relation to diffusionRe - inertia (advection) in relation to viscouseffects(laminar)
TO MIX IN TENS OF MICROSECONDS Austin et al, PRL (2002)
On the order of30 nm in the extreme cases
Hydrodynamic Focusing
Circular micromixing
Circular micromixer
Quake, Scherer (2001)
Circular mixer
In chaotic regimes, two close particles separate exponentiallyIn confined systems, this property is extremely favorable to mixing,
From Ottino’s book : « Chaotic Advection »
Thermal actuator
Micromixer
J. Evans, D. Liepmann, D., and A.P. Pisano, 1997, “Planar Laminar Mixer,” Proceeding of the IEEE 10th Annual Workshop of Micro Electro Mechanical Systems (MEMS ’97), Nagoya, Japan, Jan, pp.96-101.
Thermal mixer
Main Flow
Time periodic transverse flow
V
-V
time
400 m
investigated by Y.K. Lee, C.M.Ho (1999), Mezic et al (1999)
Fluid A
FluidB
Advection mixer
U
Perturbation is appliedLine is stretched
Perturbationis stoppedLine is folded
U
U
200m
25m
1mm
actuation channel
Glass slide Working channel
Microvalve
Micro-valve
QuickTime™ et un décompresseurH.263 sont requis pour visualiser
cette image.
Actuationpressure(bar)
Frequency (Hz)
RESONANCESMAY BE USED TO SORTPARTICLES :
BY CHANGING THE FREQUENCY OF THE PERTURBATION, ONEOBTAINS A SYSTEM WHICH MIXES FLUIDS, FILTERS PARTICLES,OR SIMPLY TRANSPORTS MATERIALS
SIDE BY SIDE.
An efficient particle sorter, using resonance
A.Dodge, P. Tabeling, A. Hountoundji, M.C.Jullien (2004)