First chronic results from a flexible sieve electrode to interface nerves without the need for guidance channels

Nerves has been previously interfaced with micro-machined sieve electrodes for recording and stimulation purposes. In most cases, so-called guidance channels have to be assembled on the sieve to adjust and fix the nerve in the vicinity of the microstructure. In this paper, a new approach of a flexible, polyimide-based sieve electrode is presented. Monolithically integrated fixation flaps offer the opportunity to directly fix the sieve implant on a transected nerve without the need for a guidance channel. The sieve has been fabricated with a thickness of 10 m and chronically implanted between the transected ends of the sciatic nerve of rats. First electrophysiological experiments proved a functional reinnervation and a selective and graded stimulation over ring electrodes around single holes of 40 m diameter in the sieve area.