A team of Oxford University scientists has developed machines 100,000 times smaller than the head of a pin that are able to reproduce themselves.

They say the techniques used to develop the so-called DNA motors, which resemble tweezers closing and opening, may lead to the production of electronic circuits 1,000 times more powerful than today's silicon chips.

The development, announced today in the British science journal Nature, was created by Oxford scientists working with a team from Bell Labs, the research and development arm of Lucent Technologies.

Bell Labs physicist Bernard Yurke, who leads the research team, said: "DNA acts as the fuel for these motors, meaning they are completely self-sufficient and do not require other chemicals to operate." The Bell Labs scientists are already working to attach DNA to molecules that conduct electricity to make molecular-scale electronic circuits.

Bell Labs, which celebrates its 75th anniversary this year, is one of the most productive research and development bodies in the world.

It has generated more than 40,000 inventions since 1925 and has worked on developing technologies from transistors, lasers and communication satellites to mobile phones and modems.

Scientists working on the project include Oxford University physicist Andrew Turberfield, physicist Allen Mills, Friedrich Simmel, of Bell Labs, and graduate student Jennifer Neumann.