World's smallest balloon
A carbon membrane only a single atom thick has been used to create a pressurised "balloon" that is impermeable to gas.
To make it, researchers at Cornell University in Ithaca, New York inflated a sheet of graphene. This is a recently discovered carbon material just one atom thick, and is tipped to succeed silicon as the basis of computing.
They created the sheets of graphene using a low-tech process dubbed "mechanical exfoliation" - using sticky tape to peel layers from a chunk of graphite.
The sheets were used to seal microscopic wells made in a layer of silica glass, forming a kind of drum head. The membranes were held in place only by the van der Waals forces that make things sticky at microscopic scales. The wells varied from 1 to 100 square micrometers in area and 250 nanometres to 3 micrometers deep.
To see how well the graphene could hold in gas, the researchers altered the pressure inside, making the graphene membranes bulge outward or inward.
Source: technology.newscientist.comAdded: 14 August 2008