Dynamics of superparamagnetic microbead transport along magnetic nanotracks by magnetic domain walls

The dynamics of fluid-borne superparamagnetic bead transport by field-driven domain walls in submicrometer ferromagnetic tracks is studied experimentally together with numerical and analytical modeling. Experiments show that nanotrack-guided domain walls can propel individual trapped beads through an aqueous medium at speeds approaching 1000 mu m/s, 10 to 100 times faster than through any previously demonstrated mechanism. (C) 2012 American Institute of Physics. [doi:10.1063/1.3684972]