text: Corrosion is a major issue with neural electrodes. Corrosion can occur because electrode metals are placed in an electrolytic solution, where the presence of current can either increase the rate of corrosion mechanisms or overcome limiting activation energies. Redox reactions are a mechanism of corrosion that can lead to dissolution of ions from the electrode surface. There is a base level of metal ions in tissue, however, when these levels increase beyond threshold values the ions become toxic and can cause severe health problems. In addition, the fidelity of the electrode system can be compromised. Knowing the impedance of an electrode is important whether the electrode is used for stimulation or recording. When degradation of the electrode surface occurs because of corrosion, the surface area increases with its roughness. Calculating a new electrode impedance to compensate for the change in surface area once implanted it is not easy. This computational flaw can skew data from recording or pose a dangerous obstacle limiting safe stimulation.