Fig. 9: Implant design and connector assembly6.
The polyimide-based device is 8 µm-thick and features a platinum metallization layer. The recording area comprises a four-by-four array (vertical and horizontal pitch of 750 µm) and each position of the array includes one large electrode (100 µm in diameter) and one small electrode (10 µm in diameter). For this study, only the large electrodes were used. Furthermore, an on-site reference electrode is included for bipolar recording configuration (not used for this study). Fenestrations on the polyimide substrate help with the drainage of fluids and promote the growth of fibrotic tissue through the holes and around the device, rather than in the space between tissue and electrodes. For mechanical stability, the thin-film interfaces the male Omnetics connector via an intermediate ceramic board.
