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, 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. (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.