Sonic screwdriver

The sonic screwdriver is a versatile tool and defensive weapon used by the Doctor from his second incarnation onwards. It is also part of the toolbox for the Doctor's TARDIS. The screwdriver was used many times by the third and fourth incarnations of the Doctor, but was destroyed when the Doctor encountered the Tereleptils and not immediately replaced (DW: The Visitation), but the Doctor (near the end of his seventh incarnation) used one just prior to his regeneration. The tool has been a ubiquitous part of the Doctor's arsenal since the destruction of Gallifrey time.

Mark I
A small, simple device very like 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 Visitation).

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)
 * 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|The Ninth and Tenth Doctor's 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 somehow make the Cybermen turn away from the Doctor's directions (possibly disrupting their systems). (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)
 * To blow doors open. (It may have just been signaling to 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--but this burnt out the screwdriver. (DW: Smith and Jones)

Mark V
The Tenth Doctor remade his screwdriver after the X-Ray incident, it was very similiar to the mark IV although somewhat larger.

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)
 * Scanning shadows for the presence of Vashta Nerada. (DW: Forest of the Dead)
 * 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, will also boast red settings and damper settings. (The nature of these settings is not yet clear.) 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).



Related Tools

 * The Sixth Doctor used a device called a sonic lance in DW: Attack of the Cybermen.


 * 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.


 * Captain Jack Harkness acquired a sonic blaster in his time travelling days, a more offensive multi-function device (DW: The Empty Child)


 * Sarah Jane Smith had a tool she called sonic lipstick. (SJA: Invasion of the Bane)


 * 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.


 * Professor River Song has a sonic blaster similiar to Captain Jack's. (DW: Silence in the Library/Forest of the Dead)

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.

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