A microelectrode for delivery of defined charge densities.
A procedure is described for fabricating microelectrodes of platinum-30% iridium, insulated with Epoxylite varnish and having beveled ellipsoidal tips obtained by truncating a conical tip at an angle of 30-50 degrees. The geometric surface area of the ellipsoidal facet is reproducible and easily measured. Using these electrodes, neurons in the cerebral cortex of cats have been activated without damage throughout 24 h or more of continuous stimulation at 15-30 microA and charge densities of 150-300 microC/cm2.phase.
D000818:Animals; D002415:Cats; D002540:Cerebral Cortex / Q000502:physiology*; D004292:Dominance, Cerebral / Q000502:physiology; D004558:Electric Stimulation / Q000295:instrumentation*; D005071:Evoked Potentials; D008839:Microelectrodes; D009482:Neurophysiology / Q000295:instrumentation*; D011712:Pyramidal Tracts / Q000502:physiology