Hermetic Encapsulation of an Implantable Vision Prosthesis – Combining Implant Fabrication Philosophies

The design of an implantable neurostimulator for the restoration of visual percepts to the blind is discussed in terms of combining two engineering philosophies derived from different origins, yet sharing a common objective. We describe the production of a very small (12 mm diameter) nerve stimulator that exclusively utilises materials with a previous history of not only biological compatibility, but also regulatory approval and clinical application. The fabrication steps that involve laser micromachining, screen-printing, and material cofiring phenomena are illustrated via the example of a substrate for a hermetic electrical neurostimulation device for long-term implantation.