Abstract

Dielectrophoretic separation of particles finds a variety of applications in the capture of species such as cells, viruses, proteins, DNA from biological systems, as well as other organic and inorganic contaminants from water. The ability to capture particles is constrained by poor volumetric scaling of separation force with respect to particle diameter, as well as the weak penetration of electric fields in the media. In order to improve the separation of sub-micron colloids, we present a scheme based on multiple interdigitated electrode arrays under mixed AC/DC bias. The use of high frequency longitudinal AC bias breaks the shielding effects through electroosmotic micromixing to enhance electric fields through the electrolyte, while a transverse DC bias between the electrode arrays enables penetration of the separation force to capture particles from the bulk of the microchannel. We determine the favorable biasing conditions for field enhancement with the help of analytical models, and experimentally demonstrate the improved capture from sub-micron colloidal suspensions with the mixed AC/DC electrostatic excitation scheme over conventional AC-DEP methods.

Original languageEnglish (US)
JournalBiomedical microdevices
Volume17
Issue number2
DOIs
StatePublished - Jan 1 2015

Keywords

  • Colloidal particle
  • Dielectrophoresis
  • Interdigitated electrodes
  • Microfluidics
  • Particle separation

ASJC Scopus subject areas

  • Biomedical Engineering
  • Molecular Biology

Fingerprint Dive into the research topics of 'Enhanced sub-micron colloidal particle separation with interdigitated microelectrode arrays using mixed AC/DC dielectrophoretic scheme'. Together they form a unique fingerprint.

Cite this