Rocket arm

Combine a mechanical arm with a miniature rocket motor: the result is a prosthetic device that is the closest thing yet to a bionic arm.

A prototype of the radical design has been successfully developed and tested by a team of mechanical engineers at Vanderbilt University as part of a $30 million federal program to develop advanced prosthetic devices.

‘Our design does not have superhuman strength or capability, but it is closer in terms of function and power to a human arm than any previous prosthetic device that is self-powered and weighs about the same as a natural arm,’ said Michael Goldfarb, the professor of mechanical engineering at Vanderbilt who is leading the effort.

The prototype can lift (curl) about 20 to 25 pounds - three to four times more than current commercial arms - and can do so three to four times faster. ‘That means it has about 10 times as much power as other arms despite the fact that the design hasn’t been optimised yet for strength or power,’ he says.