Rat-propelled robot 'could mend spacecraft'

Scientists have made the first robot driven by living muscle power. Measuring half the width of a human hair, the silicon micromachine crawls on legs powered by pulsing fibres of heart muscle from rats.

The research was funded by Nasa to design a 'musclebot' that could repair tiny meteorite punctures on spacecraft. But scientists also hope it could one day help paralysed people breathe without a ventilator. The device is an arch of silicon with a cord of heart muscle fibres underneath. As the muscle - fuelled by glucose - contracts and relaxes, it crawls along at up to 40 micrometres per second.

But microengineer Carlos Montemagno, of California University, said it could be decades before they could mend spacecraft. The issue of microbots talking to each another 'hasn't even been addressed', he told New Scientist.