Bushy bundles of carbon nanotubes

This tangled mess may look like a clown wig, but it’s actually a mass of multi-walled carbon nanotubes snapped under an electron microscope.

Carbon nanotubes are made from a single-atom-thick sheet of carbon called graphene rolled into a cylinder. Multi-walled carbon nanotubes have multiple tubes, decreasing in diameter, inside each other – like Russian nesting dolls.