Optimizing recording capabilities of the Utah Intracortical Electrode Array.

The Utah Intracortical Electrode Array is a unique silicon-based monolithic structure designed for use as a multichannel interface to the central nervous system. In this paper, we describe a series of acute experiments designed to determine the neural recording capabilities of this electrode array and the dependence of the signal-to-noise ratio (SNR) of the recordings on the electrode surface area (length of metallized tip). We found that both separable unit and multiunit cluster responses could be recorded. Additionally, high SNR recordings could be achieved for some electrodes (with electrode tip lengths of 30-220 microns), while recordings with signals substantially greater than the noise could be made from most of the electrodes provided that the proper electrode surface area was used. The demonstrated recording capabilities of the Utah Intracortical Electrode Array and its unique three-dimensional structure should form the basis for innovative physiological investigations into the functional organization of the cortex as well as for long term neuroprosthesis development.