Graphene's outstanding mechanical strength and electronic properties make it a promising material for a wide range of future applications.

But its almost ethereal thinness makes it easily damaged when working with it.

The study, published in Nano Letters, suggests it can be repaired by simply exposing it to loose carbon atoms.

It was carried out by researchers at the University of Manchester, UK - including Konstantin Novoselov, who shared a Nobel prize as graphene's co-discoverer - and at the SuperStem Laboratory of the Engineering and Physical Sciences Research Council in Daresbury, UK.

The team was initially interested in the effects of adding metal contacts to strips of graphene, the only way to exploit its phenomenal electronic properties.

The process routinely creates holes in the atom-thick sheets, so the researchers were trying to understand how those holes form, firing electron beams through graphene sheets and then studying the results with an electron microscope.

But to their surprise, they found that when carbon atoms were also near the samples, the atoms snapped into place, repairing the two-dimensional sheet.