Implantable micro-electrodes for electrical stimulation of neurons and recording neuronal responses are essential tools for neurophysiologists studying the behavior of neurons in the brain, spinal cord and peripheral nerve. Critical properties of an electrode interface include: low noise, low impedance, biocompatibility, and electrical stability during chronic use, and high charge capacity. Iridium oxide has all of these properties and thus has been utilized for significant developments in the neural prostheses arena. However, these electrodes have several shortcomings, including: high materials cost, labor-intensive processing, and deterioration of long-term stability. Foster-Miller proposes to demonstrate improved performance of neural electrodes imparted by high porosity, high surface area carbon nanotube electrodes. Nanotubes promise high electrochemically active surface area in a high porosity, high conductivity electrode, and leading to higher safe charge injection density at shorter pulse durations. They also will provide electrochemical charging in capacitively coupled monophasic pulse mode, lower cost, and improved electrochemical stability. Through this program, Foster-Miller will develop a suitable process for mass fabrication of nanotube electrode arrays, and characterize the performance of these arrays in in-vitro and in-vivo environments. Success in Phase I will lead to process design and long-term testing of prototype nanotube electrode arrays during Phase II. ? ? ?
