Cyber-filament

Cyber-filament was a form of artifical flesh tissue used by the Cybermen on Pete's World to connect artificial devices such as earpieces directly to the human brain. Infiltrating the Torchwood Tower of N-Space in 2007, the Cybermen cyber-converted Adeola Oshodi, Gareth Evans and Matt Crane into drones controlled through earpieces connected via cyber-filaments. The Tenth Doctor was forced to terminate them by overloading their signals via the sonic screwdriver. Baffled as to how they could be controlled with simple communications devices, Yvonne Hartman yanked the device out of Adeola's ear only to find, much to her disgust, a string of squelching wet brain tissue which she promptly dropped with a splat. (TV: Army of Ghosts)

Learning from Martha Jones that Adeola was her cousin, the Tenth Doctor recalled with discomfort the sight of her earpiece being wrenched away, taking Cyber-filament from her ear with it. (PROSE: Made of Steel)

Behind the scenes

 * The name "Cyber-filament" was used in Made of Steel to describe the unidentified brain tissue from Army of Ghosts.