Microcoils for transport of magnetic beads

Integrated magnetic devices were fabricated, consisting of arrays of microcoils of a novel structure, embedded in a silicon substrate, with small conductors asymmetrically shaped and with ferromagnetic pillars made of a magnetic alloy (NiCoP) as magnetic cores. These structures generated large magnetic field gradients that very effectively attracted magnetic beads. By alternatively injecting currents in an array of such microcoils placed in a microfluidic chamber, magnetic beads were guided in different movement modes and step sizes in a continuous flow. (c) 2006 American Institute of Physics.