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Experimental and numerical investigation of a scaled-up passive micromixer using fluorescence technique

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Abstract

The present paper investigates experimentally and numerically a scaled-up micromixer that combines the mixing principles of focusing/diverging and flow split-and-recombine. The micromixer consists of two units called “cross” and “omega”, which are similar to a zigzag structure. The total length is 199.5 mm with a depth of 3 mm. Fluorescence technique is used in the present study for local quantitative measurements of concentration. Two syringe pumps are used to supply the working fluids at two inlets. The testing range of Reynolds number is at 1 ≤ Re ≤ 50. The results of the experiment, obtained by fluorescence technique, are supported by the mixing visualization. The experimental results show that the mixing efficiency decreases at Re ≤ 10 and increases at Re ≥ 10. This is caused by the change in mixing mechanism from mass-diffusion domination to mass-convection domination. After five cells, the mixing efficiency reaches to 70% at Re = 50. The computational fluid dynamics is applied to assist in the understanding of fluid characteristics in channels. The simulation has a good agreement with the experiment. Based on the simulation results, vortices are observed in the channels at high Re, which could stretch and fold the fluids to enhance the effect of mass-convection on mixing. This design has the potential to be developed for micromixers with high flow rates.

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Abbreviations

A :

Interface area (m2)

B :

Ratio between intensity and concentration

C :

Concentration (μg/l)

C i :

Concentration at ith position (μg/l)

\( \bar{C} \) :

Average concentration (μg/l)

C(x, y):

Local dye concentration (μg/l)

C ref :

Reference concentration (μg/l)

\( C^{\prime}_{x} \) :

Concentration gradient in x-direction (μg/l·m)

D :

Diffusion coefficient (m2/s)

D H :

Hydraulic diameter (m)

H :

Height of channel (mm)

I f :

Local fluorescence intensity

I ref :

Reference fluorescence intensity

L :

Length of test-section (mm)

L t :

Diffusion path (m)

M :

Mixing efficiency

\( \dot{m} \) :

Mass flow rate (kg/s)

N :

Total number of sampling

P :

Pressure (Pa)

t d :

Diffusion time (s)

U :

Average velocity (m/s)

V :

Velocity vector (m/s)

W :

Width of channel (mm)

\( \text{Re} \) :

Reynolds number

\( {\text{Pe}} \) :

Péclet number

μ :

Viscosity of working fluids (N·s/m2)

ρ :

Density of working fluid (kg/m3)

m:

Micro-scale mixer

s:

Scaled-up mixer

References

  • Angele KP, Suzuki Y, Miwa J, Kasagi N (2006) Development of a hig-speed scanning micro PIV system using a rotating disc. Meas Sci Technol 17:1639–1646

    Article  Google Scholar 

  • Bhagat AAS, Peterson ETK, Papautsky I (2007) A passive planar micromixer with obstructions for mixing at low Reynolds numbers. J Micromech Microeng 17:1017–1024

    Article  Google Scholar 

  • Branebjerg J, Gravesen P, Krog JP, Nielsen CR (1996) Fast mixing by lamination. In: Proceedings. IEEE, the ninth annual international workshop on micro electro mechanical systems. An investigation of micro structures, sensors, actuators, machines and systems, pp 441–446

  • Chang CC, Yang RJ (2007) Electrokinetic mixing in microfluidic systems. Microfluid Nanofluid 3:501–525

    Article  MathSciNet  Google Scholar 

  • Chow AW (2002) Lab-on-a-chip: opportunities for chemical engineering. AIChE J 48:1590–1595

    Article  Google Scholar 

  • Chung CK, Shih TR (2008) Effect of geometry on fluid mixing of the rhombic micromixers. Microfluid Nanofluid 4:419–425

    Article  Google Scholar 

  • Chung CK, Wu CY, Shih TR (2008) Effect of baffle height and Reynolds number on fluid mixing. Microsyst Technol 14:1317–1323

    Article  Google Scholar 

  • Hardt S, Schönfeld F (2003) Laminar mixing in different interdigital micromixers: II. Numerical simulations. AIChE J 49:578–584

    Article  Google Scholar 

  • Hardt S, Drese KS, Hessel V, Schonfeld F (2005) Passive micromixers for applications in the microreactor and μTAS fields. Microfluid Nanofluid 1:108–118

    Article  Google Scholar 

  • Hessel V, Hardt S, Löwe H, Schönfeld F (2003) Laminar mixing in different interdigital micromixers: I. Experimental characterization. AIChE J 49:566–577

    Article  Google Scholar 

  • Hoffmann M, Schluter M, Rabiger N (2006) Experimental investigation of liquid-liquid mixing in T-shaped micro-mixers using μ-LIF and μ-PIV. Chem Eng Sci 61:2968–2976

    Article  Google Scholar 

  • Hong CC, Choi JW, Ahn CH (2004) A novel in-plane passive microfluidic mixer with modified Tesla structures. Lab Chip 4:109–113

    Article  Google Scholar 

  • Hsieh SS, Huang YC (2008) Passive mixing in micro-channels with geometric variations through μPIV and μLIF measurements. J Micromech Microeng 18:065017

    Article  Google Scholar 

  • Kim DS, Lee SW, Kwon TH, Lee SS (2004) A barrier embedded chaotic micromixer. J Micromech Microeng 14:798–805

    Article  Google Scholar 

  • Law AWK, Wang H (2000) Measurement of mixing processes with combined digital particle image velocimetry and planar laser induced fluorescence. Exp Thermal Fluid Sci 22:213–229

    Article  Google Scholar 

  • Lee J, Kwon S (2009) Mixing efficiency of a multilamination micromixer with consecutive recirculation zones. Chem Eng Sci 64:1223–1231

    Article  Google Scholar 

  • Lee NY, Yamada M, Seki M (2005) Development of a passive micromixer based on repeated fluid twisting and flattening, and its application to DNA purification. Anal Bioanal Chem 383:776–782

    Article  Google Scholar 

  • Lin YC, Chung YC, Wu CY (2007) Mixing enhancement of the passive microfluidic mixer with J-shaped baffles in the tee channel. Biomed Microdevices 9:215–221

    Article  Google Scholar 

  • Liu RH, Stremler MA, Sharp KV, Olsen MG, Santiago JG, Adrian RJ, Aref H, Beebe DJ (2000) Passive mixing in a three-dimensional serpentine microchannel. J Microelectromech Syst 9:190–197

    Article  Google Scholar 

  • Liu RH, Yang J, Pindera MZ, Athavale M, Grodzinski P (2002) Bubble-induced acoustic micromixing. Lab Chip 2:151–157

    Article  Google Scholar 

  • Mengeaud V, Josserand J, Girault HH (2002) Mixing processes in a zigzag microchannel: finite element simulations and optical study. Anal Chem 74:4279–4286

    Article  Google Scholar 

  • Park SJ, Kim JK, Park J, Chung S, Chung C, Chang JK (2004) Rapid three-dimensional passive rotation micromixer using the breakup process. J Micromech Microeng 14:6–14

    Article  Google Scholar 

  • Ribeiro N, Green M, Charron M (2008) Assessment of multiple intravenous pumps infusing into a single site. J Nucl Med Technol 36:88–90

    Article  Google Scholar 

  • Shinohara K, Sugii Y, Hibara A, Tokeshi M, Kitamori T, Okamoto K (2005) Rapid proton diffusion in microfluidic devices by means of micro-LIF technique. Exp Fluids 1:117–122

    Article  Google Scholar 

  • Soleymani A, Kolehmainen E, Turunen I (2008) Numerical and experimental investigations of liquid mixing in T-type micromixers. Chem Eng J 135:219–228

    Article  Google Scholar 

  • Stone HA, Stroock AD, Ajdari A (2004) Engineering flows in small devices: microfluidics toward a lab-on-a-chip. Annu Rev Fluid Mech 36:381–411

    Article  Google Scholar 

  • Vanapalli SA, Van den Ende D, Duits MHG, Mugele F (2007) Scaling of interface displacement in a microfluidic comparator. Appl Phy Lett 90:114109

    Article  Google Scholar 

  • Verpoorte E (2002) Microfluidic chips for clinical and forensic analysis. Electrophoresis 23:677–712

    Article  Google Scholar 

  • Vivek V, Kim ES (2000) Novel acoustic-wave micromixer. In: Proceedings IEEE thirteenth annual international conference on micro electro mechanical systems, pp 668–673

  • Walker DA (1987) A fluorescence technique for measurement of concentration in mixing liquids. J Phys E (Scientific Instruments) 20:217–224

    Article  Google Scholar 

  • Wang L, Yang JT, Lyu PC (2007) An overlapping crisscross micromixer. Chem Eng Sci 62:711–720

    Article  Google Scholar 

  • Zhang Z, Zhao P, Xiao G, Lin M, Cao X (20080 Focusing-enhanced mixing in microfluidic channels. Biomicrofluidics 2, p 014101-1-9

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Correspondence to Ibrahim Hassan.

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Fan, Y., Hassan, I. Experimental and numerical investigation of a scaled-up passive micromixer using fluorescence technique. Exp Fluids 49, 733–747 (2010). https://doi.org/10.1007/s00348-010-0846-8

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  • DOI: https://doi.org/10.1007/s00348-010-0846-8

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