Method of making submicrometer microelectrodes

Abstract

Microelectrodes and methods for making the same are disclosed which have electrode tip diameter of less than 10 .mu.m. The microelectrodes include a tapered electrode wire sealed in, and surrounded by, a tapered insulator tube. In one preferred embodiment, an annealed platinum wire approximately 75 .mu.m in diameter is inserted in an insulator tube, such as a borosilicate pipette, having an inner diameter of approximatley 600 .mu.m. The pipette is heated to the softening temperature of borosilicate and drawn using a conventional pulling technique. As the inner diameter of the pipette draws down, it engages the annealed platinum wire and causes the wire to also draw down in diameter. Careful selection of the relative diameters of the pipette and the platinum wire ensure that the two will break at essentially the same time thereby forming a microelectrode having a platinum disk electrode of less than 10 .mu.m diameter. Other metals, including gold, copper, silver, rhodium, iridium, tungsten and molybdenum can be used for the electrode wire.

Dependencies are inferred from the claim text.