Perception filaments

"Frankly, Master Luke, I think splashing around in the water before we abandoned ship may have corroded his perception filaments because I don't detect--"

- C-3PO about R2-D2

Perception filaments were components of R2-series astromech droids like R2-D2. They could be corroded by water, according to C-3PO.

Appearances

 * Star Wars 12: Doomworld!