Biomedical Microdevices

, Volume 9, Issue 2, pp 195–205

Quantitative characterization of magnetic separators: Comparison of systems with and without integrated microfluidic mixers

  • Torsten Lund-Olesen
  • Henrik Bruus
  • Mikkel Fougt Hansen


We present two new types of microfluidic passive magnetic bead separator systems as well as methods for performing quantitative characterizations of them. Both systems consist of a microfluidic channel with long rectangular magnetic elements of permalloy that are placed by the sides of the channel and magnetized by an external magnetic field. In one of the systems, a staggered herringbone microfluidic mixer is integrated in the channel. The characterization of the systems includes magnetic measurements of the capture-and-release efficiencies, estimates of distributions of captured beads in a channel from micrographs, and simulations and analytical models of bead trajectories, capture efficiencies, and capture distributions. We show that the efficiencies of both systems compare favorably to those in the literature. For the studied geometries, the mixer is demonstrated to increase the bead capture-and-release efficiency for a fixed flow rate by up to a factor of two. Moreover, high capture efficiencies can be achieved in the system with mixer at up to ten times higher flow rates than in the system without mixer.


Magnetic beads Magnetic separation Microfluidic Bioseparation Lab on a chip 


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Copyright information

© Springer Science+Business Media, LLC 2006

Authors and Affiliations

  • Torsten Lund-Olesen
    • 1
  • Henrik Bruus
    • 1
  • Mikkel Fougt Hansen
    • 1
  1. 1.MIC—Department of Micro and Nanotechnology, DTUTechnical University of DenmarkKongens LyngbyDenmark

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