Diamond penetrating electrode array for epi-retinal prosthesis.

This paper presents progress in the characterization and application of diamond penetrating electrode arrays for Epi-Retinal Prostheses. Electrical stimulation of degenerate retina has already been shown to restore partial vision for some blind patients, albeit at low spatial resolution. Higher resolution may be achievable by building arrays with electrodes that have greater areal density and closer proximity to target neurons. However, high standards of biocompatibility and hermeticity must be maintained, limiting the range of available materials of manufacture. Here, the design and histology of high density electrode arrays (approximately 100 electrodes/mm(2)) made from polycrystalline diamond and implanted into rat retinae are discussed. Results from initial steps in this process are reported.