Microfabricated system for magnetic field generation and focusing

A micro-coil device for the generation, focusing and manipulation of magnetic fields and the exertion of magnetic forces on magnetizable particles thereby, comprising:

• a substrate having an upper and a lower surface;
• a micro-coil, formed of a plated conductor having an aspect ratio greater than 3/1, formed in a variety of geometrical shapes on the upper surface of the substrate or in a trench formed through said upper surface and said micro-coil having at least two ends electrically connected to bonding pads for making electrical connections to said micro-coil whereby a current can be introduced into said micro-coil to produce a magnetic field thereat;
• a passivating oxide layer formed over said micro-coil;
• a dielectric layer formed over said oxide layer;
• and
• at least one pillar formed of ferromagnetic material having a high permeability, said pillar having an upper and lower end, said pillar being located at a position of maximum magnetic field strength generated by said micro-coil and the lower end of said pillar contacting a patterned metal base formed on said oxide and the upper end of said pillar extending through said dielectric layer.