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Asymmetric temporal variation of oscillating AC electroosmosis with a steady pressure-driven flow

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Abstract

In most electrokinetic flows in micro-/nanofluidics, electroosmotic flow (EOF) is always a fundamental phenomenon. When an external AC electric field is applied, there will be a transient EOF velocity, which is crucial for understanding the mechanism of the unsteady AC EOF. However, the transient flow velocity cannot be experimentally measured with sufficiently and simultaneously temporal and spatial resolution. Here we report that under a strong AC electric field, an asymmetric temporal variation of oscillating EOF (OEOF) can be generated near the electric double layer (EDL) on the bottom wall of a microchannel. The flow is measured by laser-induced fluorescence photobleaching anemometer (LIFPA). Both the flow velocity of the OEOF and the linearly related internal electric field in the microchannel are theoretically governed by an inviscid Burgers’ equations with an external forcing term and controlled by two coefficients which represent the magnitudes of linear (\({Z}_{l}\)) and nonlinear (\({Z}_{nl}\)) terms. These two coefficients are separately determined by five dimensionless parameters, including Stokes number (\({St}\)), aspect ratio (\(\gamma\)), Schmidt number (\({Sc}\)), Peclet number of mean flow velocity (\({P}_{e, U}\)) and Peclet number of electrophoresis (\({P}_{e, {EP}}\)). In this work, the influence of \({P}_{e, U}\) and \({P}_{e, {EP}}\) which are tightly related to the local mean flow velocity and the amplitude of AC electric field is investigated. When the electric field is low, \({P}_{e, U}\gg {P}_{e,{EP}}\) and accordingly \({Z}_{l}\gg {Z}_{nl}\), a temporal symmetry of the time series of velocity is observed. However, when the electric field is high, \({P}_{e, U}\ll {P}_{e, {EP}}\) and \({Z}_{l}\ll {Z}_{nl}\), then the periodicity and temporal symmetry of OEOF can be significantly broken and a temporal asymmetry of the time series of velocity is resulted in, especially under the square wave external electric field. We also find increased mean flow velocity and saturation of velocity fluctuations with the increasing electric field. This work provides a new methodology to study unsteady electrokinetic flows.

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References

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

    Article  Google Scholar 

  • Chung C-C, Glawdel T, Ren CL, Chang H-C (2015) Combination of ac electroosmosis and dielectrophoresis for particle manipulation on electrically-induced microscale wave structures. J Micromech Microeng 25:035003

    Article  Google Scholar 

  • Davidson SM, Andersen MB, Mani A (2014) Chaotic induced-charge electro-osmosis. Phys Rev Lett 112:128302

    Article  Google Scholar 

  • Fiedler HE, Mensing P (1985) The plane turbulent shear layer with periodic excitation. J Fluid Mech 150:281–309

    Article  Google Scholar 

  • Hojgaard Olesen L, Bazant MZ, Bruus H (2010) Strongly nonlinear dynamics of electrolytes in large ac voltages. Phys Rev E Stat Nonlin Soft Matter Phys 82:011501. https://doi.org/10.1103/PhysRevE.82.011501

    Article  Google Scholar 

  • Karatay E, Druzgalski CL, Mani A (2015) Simulation of chaotic electrokinetic transport: performance of commercial software versus custom-built direct numerical simulation codes. J Colloid Interface Sci 446:67–76

    Article  Google Scholar 

  • Kirby BJ (2010) Micro- and nanoscale fluid mechanics: transport in microfluidic devices. Cambridge University Press, New York

    Book  Google Scholar 

  • Kuang C, Wang G (2010) A novel far-field nanoscopic velocimeter for nanofluidics. Lab-on-a-Chip 10:240–245

    Article  Google Scholar 

  • Kuang C, Qiao R, Wang G (2011) Ultrafast measurement of transient electroosmotic flow in microfluidics. Microfluid Nanofluid 11:353–358

    Article  Google Scholar 

  • Levitan JA, Devasenathipathy S, Studer V et al (2005) Experimental observation of induced-charge electro-osmosis around a metal wire in a microchannel. Colloids Surf A 267:122–132. https://doi.org/10.1016/j.colsurfa.2005.06.050

    Article  Google Scholar 

  • Liu W, Ren Y, Tao Y, Yao B, Li Y (2018) Simulation analysis of rectifying microfluidic mixing with field-effect-tunable electrothermal induced flow. Electrophoresis 39:779–793. https://doi.org/10.1002/elps.201700234

    Article  Google Scholar 

  • Liu W, Ren Y, Xue R, Song C, Wu Q (2020) On ion transport regulation with field-effect nonlinear electroosmosis control in microfluidics embedding an ion-selective medium. Electrophoresis 41:778–792. https://doi.org/10.1002/elps.201900408

    Article  Google Scholar 

  • Ng WY, Goh S, Lam YC, Yang C, Rodríguez I (2009) DC-biased AC-electroosmotic and AC-electrothermal flow mixing in microchannels. Lab Chip 9:802–809

    Article  Google Scholar 

  • Olesen LH, Bazant MZ, Bruus H (2010) Strongly nonlinear dynamics of electrolytes in large ac voltages. Phys Rev E 82:011501

    Article  Google Scholar 

  • Posner JD, Santiago JG (2006) Convective instability of electrokinetic flows in a cross-shaped microchannel. J Fluid Mech 555:1–42. https://doi.org/10.1017/S0022112005008542

    Article  MATH  Google Scholar 

  • Posner JD, Pérez CL, Santiago JG (2012) Electric fields yield chaos in microflows. PNAS 109:14353–14356

    Article  Google Scholar 

  • Ramos A (2011) Electrokinetics and electrohydrodynamics in microsystems. Springer, Berlin

    Book  Google Scholar 

  • Ren Y, Liu W, Tao Y, Hui M, Wu Q (2018) On AC-field-induced nonlinear electroosmosis next to the sharp corner-field-singularity of leaky dielectric blocks and its application in on-chip micro-mixing. Micromachines (Basel) 9:102. https://doi.org/10.3390/mi9030102

    Article  Google Scholar 

  • Roberts AJ (2001) Holistic discretization ensures fidelity to Burgers’ equation. Appl Numeric Mathe 37:371–396

    Article  MathSciNet  Google Scholar 

  • Rubinstein SM, Manukyan G, Staicu A et al (2008) Direct observation of a nonequilibrium electro-osmotic instability. Phys Rev Lett 101:236101

    Article  Google Scholar 

  • Saka H, Ueda Y, Nishihara K, Ilegbusi OJ, Iguchi M (2015) Transition phenomena and velocity distribution in constant-deceleration pipe flow. Exp Thermal Fluid Sci 62:175–182

    Article  Google Scholar 

  • Schnitzer O, Yariv E (2014) Nonlinear oscillations in an electrolyte solution under ac voltage. Phys Rev E 89:032302

    Article  Google Scholar 

  • She ZS, Aurell E, Frisch U (1992) The inviscid Burgers equation with initial data of Brownian type. Commun Math Phys 148:623–641

    Article  MathSciNet  Google Scholar 

  • Squires TM, Bazant MZ (2004) Induced-charge electro-osmosis. J Fluid Mech 509:217–252

    Article  MathSciNet  Google Scholar 

  • Suresh V, Homsy GM (2004) Stability of time-modulated electroosmotic flow. Phys Fluids 16:2349

    Article  Google Scholar 

  • Wang GR (2005) Laser induced fluorescence photobleaching anemometer for microfluidic devices. Lab Chip 5:450–456

    Article  Google Scholar 

  • Wang G, Yang F, Zhao W (2014) There can be turbulence in microfluidics at low Reynolds number. Lab Chip 14:1452–1458. https://doi.org/10.1039/C3LC51403J

    Article  Google Scholar 

  • Wang G, Yang F, Zhao W (2016a) Micro electrokinetic turbulence in microfluidics at low Reynolds number. Phys Rev E 93:013106

    Article  Google Scholar 

  • Wang G, Yang F, Zhao W, Chen C-P (2016b) On micro-electrokinetic scalar turbulence in microfluidics at low Reynolds number. Lab Chip 16:1030–1038. https://doi.org/10.1039/c5lc01541c

    Article  Google Scholar 

  • Werkhoven BL, Everts JC, Samin S, van Roij R (2018) Flow-induced surface charge heterogeneity in electrokinetics due to stern-layer conductance coupled to reaction kinetics. Phys Rev Lett 120:264502. https://doi.org/10.1103/PhysRevLett.120.264502

    Article  Google Scholar 

  • Wu Y, Ren Y, Tao Y, Hou L, Hu Q, Jiang H (2017) A novel micromixer based on the alternating current-flow field effect transistor. Lab Chip 17:186–197

    Article  Google Scholar 

  • Xu D, Varshney A, Ma X et al (2020) Nonlinear hydrodynamic instability and turbulence in pulsatile flow. Proc Natl Acad Sci 117:11233–11239

    Article  Google Scholar 

  • Yang F, Yang X, Jiang H et al (2010) Dielectrophoretic separation of colorectal cancer cells. Biomicrofluidics 4:13204

    Article  Google Scholar 

  • Yossifon G, Chang H-C (2008) Selection of nonequilibrium overlimiting currents: universal depletion layer formation dynamics and vortex instability. Phys Rev Lett 101:254501

    Article  Google Scholar 

  • Zhao W, Yang F, Khan J, Reifsnider K, Wang G (2015) Corrections on LIFPA velocity measurements in microchannel with moderate velocity fluctuations. Exp Fluids 56:39. https://doi.org/10.1007/s00348-014-1850-1

    Article  Google Scholar 

  • Zhao W, Yang F, Khan J, Reifsnider K, Wang G (2016a) Measurement of velocity fluctuations in microfluidics with simultaneously ultrahigh spatial and temporal resolution. Exp Fluids 56:11. https://doi.org/10.1007/s00348-015-2106-4

    Article  Google Scholar 

  • Zhao W, Yang F, Khan J, Reifsnider K, Wang G (2016b) Measurement of velocity fluctuations in microfluidics with simultaneously ultrahigh spatial and temporal resolution. Exp Fluids 57:1–12. https://doi.org/10.1007/s00348-015-2106-4

    Article  Google Scholar 

  • Zhao W, Liu X, Yang F et al (2018) Study of oscillating electroosmotic flows with high temporal and spatial resolution. Anal Chem 90:1652–1659

    Article  Google Scholar 

Download references

Acknowledgements

We appreciate the discussion with Zirui Li. The work was supported by National Natural Science Foundation of China (No. 11672229, 61775181, 51927804), the Natural Science Foundation of the Education Department of the Shaanxi Provincial Government (No. 17JK0760), the Natural Science Basic Research Program of Shaanxi Province-Major Basic Research Project (S2018-ZC-TD-0061), and NSF of US (CAREER CBET-0954977 and CBET-1336004), respectively.

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Author notes

  1. Zhongyan Hu and Tianyun Zhao made equal contribution to this work.

Authors and Affiliations

  1. State Key Laboratory of Photoelectric Technology and Functional Materials, International Scientific and Technological Cooperation Base of Photoelectric Technology and Functional Materials and Application, Institute of Photonics and Photon-Technology, Northwest University, Xi’an, 710069, China

    Zhongyan Hu, Wei Zhao, Kaige Wang & Jintao Bai

  2. School of Automation, Northwestern Polytechnical University, Xi’an, 710072, China

    Tianyun Zhao

  3. Aeronautics Engineering College, Air Force Engineering University, Xi’an, 710038, China

    Hongxun Wang

  4. Department of Mechanical Engineering and Biomedical Engineering Program, University of South Carolina, Columbia, SC, 29208, USA

    Guiren Wang

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  1. Zhongyan Hu
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  2. Tianyun Zhao
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  4. Wei Zhao
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Correspondence to Wei Zhao or Guiren Wang.

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Hu, Z., Zhao, T., Wang, H. et al. Asymmetric temporal variation of oscillating AC electroosmosis with a steady pressure-driven flow. Exp Fluids 61, 233 (2020). https://doi.org/10.1007/s00348-020-03060-z

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