The effect of site placement within silicon microelectrodes on the long-term electrophysiological recordings

Intracortical microelectrodes can be used to treat various neurological disorders given their capabilities to interface with single or multiple populations of neurons. However, most of these penetrating devices have been reported to fail over time, within weeks to months, putatively due to the foreign body response (FBR) which persistently aggravates the surrounding brain tissues. A number of studies have confirmed that various electrode properties, such as size, shape, and surface area, may play a role in the biological responses to the microelectrode. Further experimental data is needed to determine the effect of these properties on the FBR and the recording performance. In this paper, we evaluate the effect of site placement using Michigan arrays with sites on the center, edge, and tip of the shank. The results show that there is significant performance variance between the center, edge, and tip sites.