Electrokinetic actuation of low conductivity dielectric liquids

R. V. Raghavan, J. Qin, L. Y. Yeo, J. R. Friend, Kenjiro Takemura, S. Yokota, K. Edamura

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Whilst electrohydrodynamic (EHD) flow actuation of dielectric fluids has been widely demonstrated, the fundamental mechanisms responsible for their behaviour is not well understood. By highlighting key distinguishing features of the various EHD mechanisms discussed in the literature, and proposing a more general mechanism based on Maxwell (electric) pressure gradients that arise due to induced polarization, we suggest that it is possible to identify the dominant EHD mechanisms that are responsible for an observed flow. We demonstrate this for a class of low conductivity dielectric fluids - Electro-Conjugate Fluids (ECFs) - that have recently been shown to exhibit EHD flow phenomena when subjected to non-uniform fields of low intensities. Careful inspection of the salient attributes of the flow, at least at low field strengths (<1 kV/cm) - for example, the absence of a threshold voltage for the onset of flow, the quadratic scaling of the flow velocity with the applied voltage, and flow from the high to the low field region - eliminate the possibility of mechanisms based on space charge. Instead, we suggest that flow can be attributed to the existence of a Maxwell pressure gradient. This is further corroborated by good agreement between our experimental results and theoretical analysis.

Original languageEnglish
Pages (from-to)287-294
Number of pages8
JournalSensors and Actuators, B: Chemical
Volume140
Issue number1
DOIs
Publication statusPublished - 2009 Jun 18

Fingerprint

Dielectric liquids
Electrohydrodynamics
low conductivity
electrokinetics
actuation
electrohydrodynamics
liquids
Pressure gradient
Fluids
pressure gradients
Threshold voltage
Electric space charge
fluids
Flow velocity
Inspection
Polarization
threshold voltage
Electric potential
inspection
space charge

Keywords

  • Electric pressure gradient
  • Electrohydrodynamics
  • Induced charge
  • Microfluidics
  • Micropumping
  • Polarization

ASJC Scopus subject areas

  • Instrumentation
  • Materials Chemistry
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering

Cite this

Raghavan, R. V., Qin, J., Yeo, L. Y., Friend, J. R., Takemura, K., Yokota, S., & Edamura, K. (2009). Electrokinetic actuation of low conductivity dielectric liquids. Sensors and Actuators, B: Chemical, 140(1), 287-294. https://doi.org/10.1016/j.snb.2009.04.036

Electrokinetic actuation of low conductivity dielectric liquids. / Raghavan, R. V.; Qin, J.; Yeo, L. Y.; Friend, J. R.; Takemura, Kenjiro; Yokota, S.; Edamura, K.

In: Sensors and Actuators, B: Chemical, Vol. 140, No. 1, 18.06.2009, p. 287-294.

Research output: Contribution to journalArticle

Raghavan, RV, Qin, J, Yeo, LY, Friend, JR, Takemura, K, Yokota, S & Edamura, K 2009, 'Electrokinetic actuation of low conductivity dielectric liquids', Sensors and Actuators, B: Chemical, vol. 140, no. 1, pp. 287-294. https://doi.org/10.1016/j.snb.2009.04.036
Raghavan, R. V. ; Qin, J. ; Yeo, L. Y. ; Friend, J. R. ; Takemura, Kenjiro ; Yokota, S. ; Edamura, K. / Electrokinetic actuation of low conductivity dielectric liquids. In: Sensors and Actuators, B: Chemical. 2009 ; Vol. 140, No. 1. pp. 287-294.
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