Flexible, Polyimide-Based Neural Interfaces

Micromachining technologies were established to fabricate microelectrode arrays and devices for interfacing parts of the central or peripheral nervous system in case of neuronal disorders. The devices were part of a neural prosthesis that allows simultaneous multichannel recording and multisite stimulation of neurons. Overcoming the brittle mechanics of silicon devices and challenging housing demands close to the nerve, we established a process technology to fabricate light-weighted and highly flexible polyimide based devices with integrated interconnects. A new assembling technique-the microflex interconnection (MFI)-has been applied for the connection of the flexible microsystems to silicon microelectronics. In this paper, we present different shapes and applications of the flexible electrodes. The discussion is focused on electrode properties and the hybrid assembly of a fully implantable neural prosthesis