The synchronization of superparamagnetic beads driven by a micro-magnetic ratchet.

TitleThe synchronization of superparamagnetic beads driven by a micro-magnetic ratchet.
Publication TypeJournal Article
Year of Publication2010
AuthorsL Gao, NJ Gottron, LN Virgin, and BB Yellen
JournalLab on a Chip
Volume10
Start Page2108
Issue16
Pagination2108 - 2114
Date Published08/2010
Abstract

We present theoretical, numerical, and experimental analyses on the non-linear dynamic behavior of superparamagnetic beads exposed to a periodic array of micro-magnets and an external rotating field. The agreement between theoretical and experimental results revealed that non-linear magnetic forcing dynamics are responsible for transitions between phase-locked orbits, sub-harmonic orbits, and closed orbits, representing different mobility regimes of colloidal beads. These results suggest that the non-linear behavior can be exploited to construct a novel colloidal separation device that can achieve effectively infinite separation resolution for different types of beads, by exploiting minor differences in their bead's properties. We also identify a unique set of initial conditions, which we denote the "devil's gate" which can be used to expeditiously identify the full range of mobility for a given bead type.

DOI10.1039/c003836a
Short TitleLab on a Chip