Multiple and Mass Transfer of Magnetic Particles for Use in Biosensors

We studied a method of collecting small magnetic particles on a narrow metallic wire and transferring them between wires by using magnetic fields of electrical currents. By applying currents to a grid pattern of wires in specified directions, we could adjust direction of thermal drift of the particles in a fluid. We could collect a large amount of particles on a wire at an elevated speed aided by the drift. Gradual changes of the currents in two parallel wires enabled us to transfer the particles between the wires at a fast rate. The transfer could be reversed multiple times by switching the direction of currents. The multiple and mass control of the magnetic particles could be used for high sensitivity biosensors.