Human contact switch?

i was wandering if anyone would be able to help, i am currently building a robot for a college project and a safety meaure i want to incorporate is human contact causes a power cut.

does any one know of any circuits that i could use to make the whole of robots structure (which is entirely metalic) sensitive to human touch?

Any advice is greatly appreciated

Cheers Will

Check out the QT110, QT112 touch sensor.
**broken link removed**