Sonic screwdriver

The sonic screwdriver was a versatile tool and defensive weapon used by the Doctor from his second incarnation onwards.

Mark I
A small, simple device similar to a penlight, first used by the Doctor in his second incarnation. (DW: Fury from the Deep)

Known Uses:
 * Opening up hatches and panels (DW: Fury from the Deep, The War Games) and control panels. (DW: The War Games)
 * As a conventional screwdriver (without touching the screws). (DW: The War Games).
 * For cutting through a section of a wall. (DW: The Dominators)



Mark II
A larger and more elaborately detailed version, the Doctor began using this model in his third incarnation. It has yellow and black stripes. (DW: The Sea Devils).

Known Uses:
 * As a means to open the shed containing garage containing the Doctor's TARDIS and Bessie. (DW: Inferno)
 * Booby trap detector in the Master's TARDIS. (DW: Colony in Space)
 * Remote detection and detonation of land mines. (DW: The Sea Devils)
 * To open an electronic door. (DW: The Mutants,
 * Undoing wrist clamps. (DW: The Mutants)
 * Detection of anti-matter. (DW: The Three Doctors)
 * Creation of a spark of fire. (DW: Carnival of Monsters)

Mark III
The Fourth Doctor remade his sonic screwdriver into a silver version that lacked the yellow and black stripes. It was capable of extending its tip.

Mark IV
In his ninth incarnation the Doctor had a new model with a glowing blue laser-like beam at one end. At the beginning of his tenth incarnation his also carried this model until it was burnt out after modifying an X-Ray scanner to give off more radiation. (DW:Smith and Jones)

Known Uses:
 * Detecting and stopping telepathic signals. (DW: Rose)
 * Interfacing with a computer. (DW: The End of the World)
 * As a medical scanner and diagnostic tool. (DW: The Empty Child)
 * Obtaining money from a cash machine. (DW: The Long Game, The Runaway Bride)
 * Battery charging. (DW: Father's Day)
 * Resonating concrete. (DW: The Empty Child)
 * Completely corroding thin metal (e.g. barbed wire) so that it crumbles into rust. (DW: The Doctor Dances)
 * Re-connecting barbed wire. (DW: The Doctor Dances)
 * Reversing teleport devices. (DW: Boom Town)
 * Dematerialising the TARDIS and initalising TARDIS processes from outside the craft. (DW: The Parting of the Ways) )[[Image:Sonic_Screwdriver_Mark_1.gif|right|thumb|130px|Later version of the sonic screwdriver]]
 * To transfer its powers to the viewer's remote control. (DW: Attack of the Graske)
 * As a lighter. (DW: The Girl in the Fireplace)
 * To make the Cybermen turn away from the Doctor's direction. (DW: The Age of Steel)
 * To cut rope. (DW: The Age of Steel)
 * To threaten the Wire. (DW: The Idiot's Lantern)
 * To partially reverse the Abzorbaloff's absorption of Ursula Blake. (DW: Love & Monsters)
 * Detonation of an explosive device. (DW: Doomsday)
 * Get money from cash machine, at both regular and extra-high rates of ejection (DW: The Runaway Bride)
 * To destroy the Robot Santas with sound. (DW: The Runaway Bride)
 * To increase the radiation output of a device such as an X-Ray scanner, burning out the screwdriver. (DW: Smith and Jones)

Mark V
The Tenth Doctor remade his screwdriver after the X-Ray incident. It was very similar to the Mark IV, though somewhat larger. The Tenth Doctor has stated that almost nothing could interfere with its operation, save for hairdryers. It does not work on wood; whether this weakness is unique to this model or common to all models is unknown.

Known Uses:
 * Breaking into several motorway cars. (DW: Gridlock)
 * Trying to strip off pieces of Dalekanium during a Solar flare. (DW: Evolution of the Daleks)
 * Bypassing and turning off security systems. (DW: The Lazarus Experiment)
 * Scanning for the transformed Lazarus Creature after it escaped to Southwark Cathedral(DW: The Lazarus Experiment)
 * Locking the TARDIS navigational systems to only allow travel between its current position and its previous position. (DW: Utopia)
 * Controlling a cable cart (DW: Partners in Crime)
 * Disabling a Sontaran teleport (DW: The Sontaran Stratagem)
 * Scanning shadows for the presence of Vashta Nerada. (DW: Forest of the Dead)
 * Showing a hologram (of Donna Noble) (DW: Forest of the Dead)
 * Teleporting a Graske to the other side of the universe (DW: Music of the Spheres)
 * As a Sonic Toothbrush. (DWAM: The Continuity Cap)

Mark VI
In the Doctor's future, he will build a new version of the screwdriver with, in addition to the Mark V settings, red settings and damper settings. (The nature of these settings is not yet clear; however, it is suggested that a red setting is a more powerful setting than the blue one and maybe dampers reduce outside interference with the sonic - similar to a Bio damper) He gave it to River Song, both for her use and because it served as a way to save River's Data Ghost for uploading into the Library's main computer. (DW: Silence in the Library/Forest of the Dead).

Known Uses
 * Activating and disabling Gravity Platforms (DW: "Forest of the Dead'').



Related Tools

 * Liz Shaw had her own sonic screwdriver, which she used to open the Doctor's TARDIS for him. (DW: Inferno)


 * This appeared like the Doctor's Mark II.


 * Romana constructed her own sonic screwdriver. Her version so impressed the Doctor that he attempted (unsuccessfully) to swap sonic screwdrivers with her. (DW: The Horns of Nimon)


 * This resembled a smaller, slimmer version of the Doctor's Mark II.


 * The Master had a similar tool called a laser screwdriver (DW: The Sound of Drums)


 * Using stolen and incomplete UNIT design plans, Toshiko Sato created a sonic modulator. (TW: Fragments)


 * Miss Foster had a sonic pen in Partners in Crime, with a similar design, described as sleek, to the Doctor's sonic screwdriver. (DW: Partners in Crime)


 * The Doctor gave Sarah Jane Smith a Sonic lipstick, a similar tool. (SJA: Invasion of the Bane)

Technology and Functions
The sonic screwdriver is apparently the product of Gallifreyan technology since other Time Lords (i.e. Romana) use the device and understand it enough to construct their own versions of it. The name of the device itself suggests that it functions using soundwaves, although the actual workings of the device have never been explained.

The different versions of the Doctor's sonic screwdrivers have exhibited different capabilities and uses, such as the interception of signals ranging from transmat beams to conscious thought; medical diagnostics and repair of organic parts; cutting, but also re-attaching together materials such as barbed wire; operating Earth machinery such as computers and even cash machines (at regular and high eject speeds); creating a spark to light a candle. Although it is primarily a tool, it can also be used as a defensive weapon, such as when the Tenth Doctor put it in a sound board to destroy the Robot Santas. (DW: The Runaway Bride) However, according to the Tenth Doctor, the device cannot be used to wound, maim or kill living things. (DW: Doomsday)

Sonic screwdrivers and similar technology cannot unlock a deadlock seal. (DW: School Reunion) Some or all versions may be ineffective against wood, or in the presence of some models of hairdryers. (DW:Silence in the Library/Forest of the Dead).

Behind the Scenes

 * The tool was retired during the Fifth Doctor serial The Visitation as it was felt it had become overused. It was absent for the Sixth Doctor TV era and all of the Seventh, except in Doctor Who: The TV Movie in which the Seventh Doctor was seen to use it to lock the Master's remains away, and the Eighth Doctor recovered it at the end of the film. The tool was reintroduced with the Ninth Doctor and has become the show's most frequently used gadget besides the TARDIS itself.


 * For unexplained reasons, the Tenth Doctor's Sonic Screwdriver had a green casing in The Infinite Quest.


 * During early production of Series 1 (2005), the production crew decided to switch from their original prop to one based on the toy Sonic Screwdriver, knowing that the fans would want a properly sized "prop" based on the show. This means that the toy and the "real" Screwdriver are the same size.


 * Many websites that offer this toy state that the Sonic Screwdriver is an extention of the TARDIS, or that it contains part of the TARDIS's essence. This is unconfirmed, though given the advanced technology used to create it, as well as its seemingly endless list list of abilities, it makes sense.  However, it does not take into account that the Doctor has actually had at least two, which were hand-built and modified.


 * There are two main versions of the Sonic Screwdriver - one has a slide feature with button, and one which does not slide and has a fixed button. The two prop types varied each episode