Method of making implantable microelectrode

Microelectrodes for use in stimulating and detecting activity in neurons of living organisms, and a method of manufacturing such microelectrodes. An electrically conductive electrode core member is sharpened and coated with a thin layer of a dielectric material. An extremely small area of the core at the sharpened point is exposed by ablating the dielectric material by the use of ultraviolet laser beam scanned over the material. Multiconductor microelectrodes include multiple fine wires which may be arranged in helical strands, optionally supported by a central core member of stiffer material. Multiple conductors may also be supported within a tubular support such as a hollow needle whose distal end is cut at a slant to expose the conductors, or in flat ribbon configuration with openings in dielectric material defining active electrode sites. Multiple active electrode sites may be defined on a microelectrode accompanied by an integrated circuit after connection of the integrated circuit to a multiconductor cable.