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Microfluidic switch based on combined effect of hydrodynamics and electroosmosis

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Abstract

This paper presents theoretical and experimental investigations on valveless microfluidic switch using the coupled effect of hydrodynamics and electroosmosis. Switching of a non-conducting fluid stream is demonstrated. The first part of the investigation focused on flow switching of a non-conducting fluid, while the second part focused on switching of aqueous liquid droplets in a continuous oil stream. Two sheath streams (aqueous NaCl and glycerol) and a sample stream (silicon oil) are introduced by syringe pumps to flow side by side in a straight rectangular microchannel. External electric fields are applied on the two sheath streams. The switching process using electroosmotic effect for different flow rate and viscosity of sample stream is investigated. The results indicate that the switching response time is affected by the electric fields, flow rate, and viscosity of the sample. At constant inlet volumetric flow rates, the sample streams or droplets can be delivered to the desired outlet ports using applied voltages.

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Abbreviations

e1, e2, e3:

Liquid fractions

e :

Elementary charge, e = 1.602 × 10−9 (C)

E x :

The electric field

G :

Parameter measuring the electroosmotic force by external electric field

h :

Height of the microchannel (m)

L ref :

The length scale

M :

Electrokinetic effect in the matching conditions

n 0 :

Ionic number concentration in the bulk (m−3)

n i :

Ionic number concentration of the type i in the bulk (m −3)

k b :

Boltzmann constant, k = 1.381 × 10−23 (J K−1)

K :

Electrokinetic parameter

p :

Pressure

q :

Flowrate

r :

Position vector (m)

Re :

Reynolds number

t :

Time (s)

T :

Temperature (K)

u :

Velocity

U ref :

The velocity scale

V:

Voltage

w :

Half of width of the channel (m)

z 0 :

The valence of the ions

p :

Density

ψ 0 :

Electrostatic potential

ξ :

Zeta potential

ɛ :

The permittivity of the dielectric

ɛ 0 :

The permittivity of the dielectric of vacuum

ɛ r :

The dielectric constant comparing with ɛ 0

ψ :

The electric potential

μ :

Dynamic viscosity

κ:

Debye–Hückel parameter (m−1)

ρ s q :

The surface charge density

β:

Dynamic viscosity ratios

ref:

Reference quantity

1:

Conducting fluid 1

2:

Non-conducting fluid 2

3:

Conducting fluid 3

q :

Charge of bulk

0:

Fundamental state

–:

Dimensionless parameter

p:

Pressure driven

E:

Electroosmotic effect

′:

Derivative

I:

Integrate

∇:

Gradient

∂:

Partial differential

References

  • Andersson H, Van den Berg H (2003) Microfluidic devices for cellomics: a review. Sens Actuators B 92(3):315–325

    Article  Google Scholar 

  • Ateya DA, Erickson JS, Howell P B Jr, Hilliard LR, Golden JP, Ligler FS (2008) The good, the bad, and the tiny: a review of microflow cytometry. Anal Bioanal Chem 391(5):1485–1498

    Article  Google Scholar 

  • Besselink GAJ, Vulto P, Lammertink RGH, Schlautmann S, van den Berg A, Olthuis W, Engbers GHM, Schasfoort RBM (2004) Electroosmotic guiding of sample flows in a laminar flow chamber. Electrophoresis 25(21–22):3705–3711

    Article  Google Scholar 

  • Braschler T, Demierre N, Nascimento E, Silva T, Oliva AG, Renaud P (2008) Continuous separation of cells by balanced dielectrophoretic forces at multiple frequencies. Lab Chip 8(2):280–286

    Article  Google Scholar 

  • Brask A, Goranović G, Jensen MJ, Bruus H (2005) A novel electro-osmotic pump design for nonconducting liquids: theoretical analysis of flow rate-pressure characteristics and stability. J Micromech Microeng 15(4):883–891

    Article  Google Scholar 

  • Campbell K, Groisman A, Levy U, Pang L, Mookherjea S, Psaltis D, Fainman Y (2004) A microfluidic 2 × 2 optical switch. Appl Phys Lett 85(25):6119–6121

    Article  Google Scholar 

  • Chen C-H, Santiago JG (2002a) Electrokinetic instability in high concentration gradient microflow. American Society of Mechanical Engineers. Fluids Engineering Division (Publication) FED 258, pp 415–418

  • Chen CH, Santiago JG (2002b) A planar electroosmotic micropump. J Microelectromech Syst 11(6):672–683

    Article  Google Scholar 

  • Chen CH, Lin H, Lele SK, Santiago JG (2005) Convective and absolute electrokinetic instability with conductivity gradients. J Fluid Mech 524:263–303

    Article  MATH  Google Scholar 

  • Dittrich PS, Manz A (2005) Single-molecule fluorescence detection in microfluidic channels-the Holy Grail in μTAS? Anal Bioanal Chem 382(8):1771–1782

    Article  Google Scholar 

  • Dittrich PS, Tachikawa K, Manz A (2006) Micro total analysis systems. Latest advancements and trends. Anal Chem 78(12):3887–3907

    Article  Google Scholar 

  • Fu LM, Yang RJ, Lee GB, Pan YJ (2003) Multiple injection techniques for microfluidic sample handling. Electrophoresis 24(17):3026–3032

    Article  Google Scholar 

  • Fu LM, Yang RJ, Lin CH, Pan YJ, Lee GB (2004) Electrokinetically driven micro flow cytometers with integrated fiber optics for on-line cell/particle detection. Anal Chim Acta 507(1):163–169

    Article  Google Scholar 

  • Gao Y, Wang C, Wong TN, Yang C, Nguyen NT, Ooi KT (2007) Electro-osmotic control of the interface position of two-liquid flow through a microchannel. J Micromech Microeng 17(2):358–366

    Article  Google Scholar 

  • Gu Y, Li D (1998) The ζ-potential of silicone oil droplets dispersed in aqueous solutions. J Colloid Interface Sci 206(1):346–349

    Article  Google Scholar 

  • Haiwang L, Wong TN, Nguyen NT (2009) Analytical model of mixed electroosmotic/pressure driven three immiscible fluids in a rectangular microchannel. Int J Heat Mass Transfer 52(19–20):4459–4469

    Article  MATH  Google Scholar 

  • Huh D, Gu W, Kamotani Y, Grotberg JB, Takayama S (2005) Microfluidics for flow cytometric analysis of cells and particles. Physiol Meas 26(3):R73–R98

    Article  Google Scholar 

  • Huh D, Bahng JH, Ling Y, Wei HH, Kripfgans OD, Fowlkes JB, Grotberg JB, Takayama S (2007) Gravity-driven microfluidic particle sorting device with hydrodynamic separation amplification. Anal Chem 79(4):1369–1376

    Article  Google Scholar 

  • Kohlheyer D, Besselink GAJ, Lammertink RGH, Schlautmann S, Unnikrishnan S, Schasfoort RBM (2005) Electro-osmotically controllable multi-flow microreactor. Microfluid Nanofluid 1(3):242–248

    Article  Google Scholar 

  • Lee JSH, Li D (2006) Electroosmotic flow at a liquid-air interface. Microfluid Nanofluid 2(4):361–365

    Article  Google Scholar 

  • Lee GB, Lin CH, Chang SC (2005) Micromachine-based multi-channel flow cytometers for cell/particle counting and sorting. J Micromech Microeng 15(3):447–454

    Article  Google Scholar 

  • Li H, Wong TN, Nguyen NT (2009) Electroosmotic control of width and position of liquid streams in hydrodynamic focusing. Microfluid Nanofluid 7:489–497

    Article  Google Scholar 

  • Lin CH, Lee GB (2003) Micromachined flow cytometers with embedded etched optic fibers for optical detection. J Micromech Microeng 13(3):447–453

    Article  Google Scholar 

  • Lin H, Storey BD, Oddy MH, Chen CH, Santiago JG (2004) Instability of electrokinetic microchannel flows with conductivity gradients. Phys Fluids 16(6):1922–1935

    Article  Google Scholar 

  • Maenaka H, Yamada M, Yasuda M, Seki M (2008) Continuous and size-dependent sorting of emulsion droplets using hydrodynamics in pinched microchannels. Langmuir 24(8):4405–4410

    Article  Google Scholar 

  • McClain MA, Culbertson CT, Jacobson SC, Ramsey JM (2001) Flow cytometry of Escherichia coli on microfluidic devices. Anal Chem 73(21):5334–5338

    Article  Google Scholar 

  • Nguyen NT (2006) Fundamentals and applications of microfluidics. Boston, Artech House

    MATH  Google Scholar 

  • Nguyen NT, Kong TF, Goh JH, Low CLN (2007) A micro optofluidic splitter and switch based on hydrodynamic spreading. J Micromech Microeng 17(11):2169–2174

    Article  Google Scholar 

  • Pan YJ, Lin JJ, Luo WJ, Yang RJ (2006) Sample flow switching techniques on microfluidic chips. Biosens Bioelectron 21(8):1644–1648

    Article  Google Scholar 

  • Pan YJ, Ren CM, Yang RJ (2007) Electrokinetic flow focusing and valveless switching integrated with electrokinetic instability for mixing enhancement. J Micromech Microeng 17(4):820–827

    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 

  • Tan YC, Lee AP (2005) Microfluidic separation of satellite droplets as the basis of a monodispersed micron and submicron emulsification system. Lab Chip 5(10):1178–1183

    Article  Google Scholar 

  • Taylor JK, Ren CL, Stubley GD (2008) Numerical and experimental evaluation of microfluidic sorting devices. Biotechnol Prog 24(4):981–991

    Article  Google Scholar 

  • Wang C, Gao Y, Nguyen NT, Wong TN, Yang C, Ooi KT (2005) Interface control of pressure-driven two-fluid flow in microchannels using electroosmosis. J Micromech Microeng 15(12):2289–2297

    Article  Google Scholar 

  • Wolfe DB, Conroy RS, Garstecki P, Mayers BT, Fischbach MA, Paul KE, Prentiss M, Whitesides GM (2004) Dynamic control of liquid-core/liquid-cladding optical waveguides. Proc Natl Acad Sci USA 101(34):12434–12438

    Article  Google Scholar 

  • Wu Z, Nguyen NT (2005) Rapid mixing using two-phase hydraulic focusing in microchannels. Biomed Microdevices 7(1):13–20

    Article  Google Scholar 

  • Wu Z, Nguyen NT, Huang X (2004) Nonlinear diffusive mixing in microchannels: theory and experiments. J Micromech Microeng 14(4):604–611

    Article  Google Scholar 

  • Yang RJ, Chang CC, Huang SB, Lee GB (2005) A new focusing model and switching approach for electrokinetic flow inside microchannels. J Micromech Microeng 15(11):2141–2148

    Article  Google Scholar 

  • Yang SY, Hsiung SK, Hung YC, Chang CM, Liao TL, Lee GB (2006) A cell counting/sorting system incorporated with a microfabricated flow cytometer chip. Meas Sci Technol 17(7):2001–2009

    Article  Google Scholar 

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Authors and Affiliations

  1. School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore

    Haiwang Li, Teck Neng Wong & Nam-Trung Nguyen

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  1. Haiwang Li
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  2. Teck Neng Wong
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  3. Nam-Trung Nguyen
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Correspondence to Teck Neng Wong.

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Li, H., Wong, T.N. & Nguyen, NT. Microfluidic switch based on combined effect of hydrodynamics and electroosmosis. Microfluid Nanofluid 10, 965–976 (2011). https://doi.org/10.1007/s10404-010-0725-x

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  • DOI: https://doi.org/10.1007/s10404-010-0725-x

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