The program objective is development of a rapid, reliable, and reproducible manufacturing process for fabrication of spiral cuff nerve electrodes, used to restore function in neurologically impaired individuals. Such devices are currently fabricated by hand in a laborious, unreliable process by cutting and gluing platinum foils to silicone rubber substrates and using hard wires for interconnects. This proposal addresses further development of thin film deposition technology to create patterned metallic layers on the silicone rubber, eliminating the need for hand construction and vastly increasing process yield and product reliability. The feasibility and proof-of-principle of the thin film approach were established in Phase I. A rapid, inexpensive method of patterning was developed using a personal computer and laser printer. Ion beam assisted deposition (IBID) was then used to deposit extremely adherent metallic layers in the appropriate pattern. Using the established stretched silicone sheet lamination technique, conductive electrodes with ideal curling and flexibility were fabricated. Phase II will optimize thin film deposition conditions to further improve film ductility and conductivity and minimize lead width. Issues surrounding mass production of the electrodes, particularly in the post-metal deposition portions of the fabrication process, will be addressed. Animal studies will be used to evaluate important properties of the devices, such as threshold power levels, grading of force, short and long-term stability of recruitment properties, and biocompatibility. This evaluation will take place at multiple centers and with various electrode designs.
