Davros's chair

Davros used a distinctive "chair" (TV: Destiny of the Daleks) as a life support system and means of mobility. (TV: Genesis of the Daleks)

Characteristics
Resembling the base unit of a Dalek's casing, the chair was coloured black with silver sensor globes. A metal brace was attached to Davros' head, and wires were plugged into his skull. Davros also had a throat microphone implant to enhance his damaged voice. He had only his right hand, which he used to operate controls on his chariot. These could perform functions for controlling doors, the Mark III travel machines, or his own life support system. As Davros had no longer any legs nor his left hand, both his spine and arm were robotically modified and plugged into the chair to allow further control of the base unit. (TV: Genesis of the Daleks)

Davros' chair had anti-gravity gravitors that enabled him to ascend to hover position, possibly an upgrade. (TV: Revelation of the Daleks)

By the time that Davros had risen to become the Emperor of the Imperial Dalek faction during the Imperial-Renegade Dalek Civil War, his life-support chariot no longer featured a button with which he could deactivate his life support, (AUDIO: The Curse of Davros) as it had when he had first met the Doctor on Skaro. (TV: Genesis of the Daleks)

At some point prior to, during or immediately after his rescue from the Last Great Time War, Davros dispensed with his skull wires and throat microphone. However, he retained his head brace. By that point, the chair itself had evidently been reconstructed; while bearing the familiar colours, its shape had been refined to match that of the contemporary Daleks. (TV: The Stolen Earth/Journey's End)

The chair also possessed a force field, one strong enough of withstanding the firepower of several concurrent gunstick blasts. (TV: The Witch's Familiar)

History
After being crippled by a bomb, Davros was given a crude wheelchair. As he worked on his early Dalek prototypes, an epiphany led him to exploit the power of fear. Repurposing much of the resources that he had been delegated, Davros constructed his chair as a way to command respect through fear. (PROSE: Davros Genesis)

At the end of the Thousand Year War, the first generation of Daleks exterminated their Kaled forebears. When they opened fire on Davros, (TV: Genesis of the Daleks) the chair's backup life-support systems activated, placing the Dalek creator in a state of suspended animation. (TV: Destiny of the Daleks) On Skaro, during the Imperial-Renegade Dalek Civil War, Davros' chair was cut in half by the chainsword wielded by Abslom Daak. In light of this, the Imperial Daleks transferred what remained of Davros' body into an Emperor Dalek casing. (COMIC: Emperor of the Daleks!, TV: Remembrance of the Daleks)

By the Last Great Time War, Davros' chair had been reconstructed. (TV: The Stolen Earth)

In the Dalek City, the Twelfth Doctor temporarily removed Davros from his chair, which he took for himself. Greeting the Daleks, the Doctor quipped that the sight of him in Davros' chair was a nightmare which all the Daleks had shared before facetiously offering to play dodgems with them. The chair was ultimately returned to Davros after Colony Sarff captured the Doctor. (TV: The Witch's Familiar)

Props
In the classic series, Davros' chair was constructed for Genesis of the Daleks. It was modified for its reprisals in Destiny of the Daleks and Resurrection of the Daleks. It appeared for the last time in Revelation of the Daleks.

For the new series, a brand new prop was constructed for Davros in The Stolen Earth/Journey's End. This prop was reprised with minor modifications for The Magician's Apprentice/The Witch's Familiar.

Anatomy
Terry Nation's Dalek Annual 1978 provided an anatomy of Davros, naming the components in his life-support system:
 * 1) Vibro-sensor
 * 2) Omnipute
 * 3) Fatigue Eliminator
 * 4) Audio input
 * 5) Transmission controls
 * 6) Energiser
 * 7) Disc sensors
 * 8) Pacemaker controls
 * 9) Circuit monitor
 * 10) Veracity perceptor
 * 11) Power source indicators
 * 12) Fail safe defence
 * 13) Dalek voice control
 * 14) Telepathic receptor
 * 15) Super optic