Figure 12.

RUS-LPFv2, 994 days. (a) An electrode with significant delamination at parylene interface and thick fibrosis at the tip, scale 10 μm, 10 kV. (b) Detail of encapsulation showing individual collagen fibers, scale 3 μm, 10 kV. (c) Top view of another electrode showing collagenous tissue growth (top) along platinum tip (bottom), scale 300 nm, 5 kV. (d) Top view of an electrode with damaged platinum tip and exposed silicon, scale 10 μm, 5 kV. (e) Top view of another electrode with an essentially intact platinum tip, scale 2 μm, 5 kV. (f) Top view of a severely degraded electrode tip. The platinum is almost completely disintegrated and the silicon beneath it shows signs of pitting corrosion. Note that there is no evidence of mechanical damage, indicating a chronic process, scale 2 μm, 5 kV. (g) Side view of yet another electrode with severe platinum corrosion, exposure of underlying silicon, and tissue invasion, scale 1 μm, 5 kV. (h) An electrode with thick fibrous encapsulation that appears to be peeling the platinum away from the exposed silicon, scale 2 μm, 5 kV. (i) Top view of a different electrode showing a swollen, possibly oxidized, platinum layer that has separated from the underlying silicon, scale 1 μm, 5 kV. (j) Detail of tissue growth between the exposed silicon and platinum, scale 200 nm, 5 kV.