The graphene foam is macroscopic in total size (left), yet has nanoscopic internal structures (right)
For some time now, scientists have known that certain nanostructures are very sensitive to the presence of various chemicals and gases, making them good candidates for use in explosives-detecting devices. Unfortunately, because they're so small, mounting a single nanostructure within such a device would be an extremely fiddly and costly process. They would also be quite fragile, plus it would be difficult to clean the detected gas from them, so they could be reused. Recently, however, scientists from New York's Rensselaer Polytechnic Institute have figured out a solution to those problems. They have created a postage stamp-sized piece of foam made from one continuous piece of graphene, that is easy to manipulate, flexible, rugged, simple to neutralize after each use ... and is ten times more sensitive than traditional polymer sensors.