Measuring the effective area and charge density of platinum electrodes for bionic devices

Abstract

Objective. Neural stimulation is usually performed with fairly large platinum electrodes. Smaller electrodes increase the applied charge density, potentially damaging the electrode. Greater understanding of the charge injection mechanism is required for safe neural stimulation. Approach. The charge injection mechanism and charge injection capacity were measured by cyclic voltammetry. Electrodes were cleaned mechanically or by potential cycling in acidic solutions. The effective electrode area was measured by hydrogen adsorption or reduction of . Main results. The water window and safe potential window were affected by changes to electrolyte, electrode size, polishing method and oxygen concen..