The experiment, believed to be the first of its kind, means a computer can keep track of the device and its carrier.

Professor Kevin Warwick: Tiny chip - enormous potential

The chip has been inserted in Professor Kevin Warwick's upper arm.

The professor, from the University of Reading, in England, is taking part in the experiment to highlight some of the dangers of the technology.

Adpating technology

The technology itself is not new. Silicon chips are already used in many countries to identify animals.

BBC science correspondent Sue Nelson reports on the experiment

A digital reader can pick up a unique code for the device which is placed under the skin.

The chips can be used to reunite lost pets with their owners and identify animals which have received vaccinations for certain diseases.

More sophisticated

The implant in Professor Warwick's body is more sophisticated. Sensors can be set up to pinpoint his location and even switch on lights automatically when he enters a room on campus.

Intelligent building can track his moves

But he says the real reason for having the chip inserted was to demonstrate the sinister side of the pushing the frontiers of technology forward.

"There are positive sides and negative sides - postive in helping people around big building, negative are the big big brother issues - machines or computers controlling humans," he said.

Professor Kevin Warwick:"It gets very frightening"

He says that if their use became widespread we would never enjoy any privacy and could be followed and identified wherever we went.

Future possibilities

Professor Warwick's device, which will be removed after a week, carries 64 pieces of information.

Old hat - electronic tags worn on the outside

But they could also be used to carry personal information such as bank details or credit ratings.

"If we look to the future, compared with what this small chip contains now, in five or six years time the amount of information and the amount of processing capabilites will be enormous," Professor Warwick said.