Planar electrode

Abstract

A planar electrode which enables multi-point simultaneous stimulation and recording of nerve cells over a long time is provided, which also has excellent response property. An ITO film is evaporated on the whole surface of an insulating substrate of the hard glass, and the ITO film is etched so that the central portion of each electrode is located on each intersection of 8.times.8 lattices, the center-to-center distances of nearest electrodes of each electrode are equal, and a lead wire is stretched radially. Then, for an insulating layer, negative photo-sensitive polyimide is spin-coated, and an insulating layer pattern is exposure-formed so that a 50 .mu.ms square hole is produced at the center of each electrode. Furthermore, to the exposed portion of each electrode (that is, the inside of the 50 .mu.ms square), Ni is evaporated in a film thickness of 500 nm, which is followed by evaporating gold (50 nm) and platinum black (about 1 .mu.m). The contact with the external circuit of the section near the end opposite to the electrode of the lead wire was coated with gold and nickel.

Dependencies are inferred from the claim text.