Buckyball technology. Computer artwork of a spherical fullerene (buckyball) enclosed between two carbon sheets. The molecular model shows the hexagonal and pentagonal carbon structure found on the surface of spherical fullerenes. Fullerenes are a structural form (allotrope) of carbon. Other forms of fullerenes include carbon nanotubes, which are cylindrical in shape. Sheets of carbon are found in a different allotrope of carbon, graphite. Theoretically, a wide range of molecular shapes can be engineered at the molecular level using fullerenes. Such structures could have a wide range of technological and medical uses.