Flexible Parylene-based Microelectrode Technology for Intraocular Retinal Prostheses

Abstract

We present the first single metal layer flexible microelectrode arrays designed for intraocular implantation that utilize parylene C as their primary structural and insulating material. These electrodes are fabricated as a key component of an intraocular retinal prosthesis comprising a radio-frequency coil for power and data transfer, a packaged high lead-count telemetry-recovery and driving application-specific integrated circuit (ASIC), and a high-density epiretinal stimulating microelectrode array for the treatment of retinal degenerative blindness in humans. Electrochemical tests have demonstrated that these thin-film platinum electrodes perform as necessary for neuronal stimulation. A novel bioconformal MEMS geometry for a complete intraocular system with capsular retaining-wings that enables all the components of the system to be implanted and retained within the lens capsule and vitreous cavity of the eye is also presented. The efficacy of this geometry when compared with a previous model without capsular retaining-wings has been verified by surgical implantation in animal models.