Patent ID: 8398295

Claim:
A device for manipulating non-magnetic particles dispersed inside a fluid comprising: a) a fluid holding chamber comprising an inner and outer surface; b) a fluid in contact with the inner surface of the fluid holding chamber, said fluid containing a dispersion of magnetic particles and a dispersion of non-magnetic particles, wherein at least one of said non-magnetic particles is not attached to said magnetic particles; and c) at least two sources of magnetic fields positioned in close proximity to, or inside of the fluid holding chamber which produce a changeable pattern of magnetic field minima and maxima regions thereby causing the non-magnetic particles in the fluid to be transported towards the magnetic field minima regions by magnetic force, wherein at least one of said sources of magnetic fields comprises an array of magnetizable features on a micrometer or nanometer length scale, and further wherein at least one of said sources of magnetic fields comprises a time-varying magnetic field supplied by a source held external to said fluid holding chamber.