Fullerene molecule, illustration. A fullerene is a structurally distinct form (allotrope) of carbon. It is made up of several carbon atoms (solid spheres) connected by both single and double bonds which form a hollow spherical structure consisting of pentagonal and hexagonal rings. This family of molecules is named after buckminsterfullerene (C60), which is the most famous molecule in the family, and named after Buckminster Fuller. Spherical fullerenes are sometimes referred to as buckyballs due to their resemblance of footballs. Fullerenes are being investigated for applications in nanotechnology, materials science, and medicine.