DEP particle dynamics and the steady drag assumption

S. T. Wereley, I. Whitacre, R. Bashir, H. B. Li

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The interaction of fluid drag, dielectrophoretic forces, and Brownian motion on a nanoparticle's motion is studied using a microfluidic chip with interdigitated electrodes. The flow domain is a 11.6 μm deep by 350 μm wide channel with 23 μm wide electrodes located at the bottom surface of the channel and a glass top surface. The electrodes are covered by a thin layer of silicon dioxide to insulate them from the fluid medium, suppressing electrolysis and local Joule heating. Although these phenomena have been considered by other researchers, our experiments and modeling reveal it to be a considerably more complicated phenomenon than previously thought. Using an adapted micro Particle Image Velocimetry technique along with microscopic imaging, particle motion in three-dimensions is measured and compared to predicted results, showing not only the expected horizontal DEP retarding force but also a vertical force away from the electrodes. Further, because of the spatially varying nature of both the DEP force as well as the drag force, one of the main assumptions made in many previous DEP studies must be seriously questioned -whether steady low Reynolds number particle dynamics are insufficient to predict the particle behavior.

Original languageEnglish (US)
Title of host publication2004 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2004
EditorsM. Laudon, B. Romanowicz
Pages320-323
Number of pages4
StatePublished - 2004
Externally publishedYes
Event2004 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2004 - Boston, MA, United States
Duration: Mar 7 2004Mar 11 2004

Publication series

Name2004 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2004
Volume1

Other

Other2004 NSTI Nanotechnology Conference and Trade Show - NSTI Nanotech 2004
Country/TerritoryUnited States
CityBoston, MA
Period3/7/043/11/04

Keywords

  • DEP
  • Dielectrophoresis
  • Particle
  • PIV
  • Velocity

ASJC Scopus subject areas

  • Engineering(all)

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