PERIPHERAL-NERVE REGENERATION THROUGH MICROELECTRODE ARRAYS BASED ON SILICON TECHNOLOGY

This paper describes some developments made to obtain a chronic neural interface to record signals from regenerated peripheral nerves. Micro perforated silicon dices, fabricated by techniques compatible with CMO S processes, were coupled in silicone nerve chambers and implanted bet ween the severed ends of peripheral nerves in rats. Three configuratio ns of perforated dices with 25 via-holes of 100 mu m diameter, 121 via -holes of 40 mu m and 400 via-holes of 10 mu m were assessed. The feas ibility of axonal regeneration through the dices via-holes was proved by histological and physiological methods over 3 months post-implantat ion. The regenerated nerves were organized in fascicles corresponding to the grid pattern of the via-holes. However, nerve regeneration was difficult and distal re-innervation delayed with respect to simple tub ulization repair. The size of the via-holes and the total open area ar e determinants of the degree and quality of regeneration. Further impr ovements are needed in both the microelectrode dice design and in neur obiological stimulation of regeneration.