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)