Scientists are planning to build a mechanical computer on a microscopic level to replace low speed silicon processors.

British pioneer Charles Babbage first began work on a steam powered mechanical computer in 1822 which used gears and levers to perform complex calculations.

Scientists at the University of Wisconsin-Madison are now planning to build similar mechanical computers using nanotechnology.

The team outlined their plans in a paper to be published in the New Journal of Physics. 

"What we are proposing is a new type of computing architecture that is only based on nano-mechanical elements," said Professor Robert Blick of the University of Wisconsin-Madison and one of the authors of the paper.

"We are not going to compete with high-speed silicon, but where we are competitive is for all of those mundane applications where you need microprocessors which can be slow and cheap as well.

"It is inspired by Babbage's ideas but these days we can scale it down."

The computer's levers would be made out of piezoelectric material that flexes under electrical current. They would also use much less power than a conventional silicon processor.

The US military is reportedly very interested in the devices, since they would not be susceptible to the electromagnetic pulses which can be generated by a nuclear explosion.