Sonic screwdriver

The sonic screwdriver is a fictional tool in the British science fiction television series Doctor Who. Its primary function is the ability to operate on virtually any lock and thus open doors, either for escape or for exploration. It has also been used as for repairing equipment, and as an offensive weapon; occasionally it is even used to drive screws. Its abilities vary somewhat from story to story and the way it works is never explicitly explained. However, the name implies that it operates through the use of sound waves to exert physical forces remotely on objects such as the mechanism inside locks. The sonic screwdriver made its first appearance in the Second Doctor serial, Fury from the Deep.

The sonic screwdriver was eventually destroyed and not replaced. Presumably the series writers found that it was too much of a deus ex machina, since the Doctor could use it to get out of just about any situation.

Sonic Screwdriver is also the name of a fanzine published by the Doctor Who Club of Victoria.