Traveling wave magnetophoresis for high resolution chip based separations.

Journal Article (Journal Article)

A new mode of magnetophoresis is described that is capable of separating micron-sized superparamagnetic beads from complex mixtures with high sensitivity to their size and magnetic moment. This separation technique employs a translating periodic potential energy landscape to transport magnetic beads horizontally across a substrate. The potential energy landscape is created by superimposing an external, rotating magnetic field on top of the local fixed magnetic field distribution near a periodic arrangement of micro-magnets. At low driving frequencies of the external field rotation, the beads become locked into the potential energy landscape and move at the same velocity as the traveling magnetic field wave. At frequencies above a critical threshold, defined by the bead's hydrodynamic drag and magnetic moment, the motion of a specific population of magnetic beads becomes uncoupled from the potential energy landscape and its magnetophoretic mobility is dramatically reduced. By exploiting this frequency dependence, highly efficient separation of magnetic beads has been achieved, based on fractional differences in bead diameter and/or their specific attachment to two microorganisms, i.e., B. globigii and S. cerevisiae.

Full Text

Duke Authors

Cited Authors

  • Yellen, BB; Erb, RM; Son, HS; Hewlin, R; Shang, H; Lee, GU

Published Date

  • December 2007

Published In

Volume / Issue

  • 7 / 12

Start / End Page

  • 1681 - 1688

PubMed ID

  • 18030387

Electronic International Standard Serial Number (EISSN)

  • 1473-0189

International Standard Serial Number (ISSN)

  • 1473-0197

Digital Object Identifier (DOI)

  • 10.1039/b713547e


  • eng