Behold the carbon nanotorus: a microscopic ring made of carbon atoms. It's diameter is about 1/1000th the thickness of a sheet of paper. We can make billions of carbon nanotubes and spheres and torii. However their geometry cannot be properly controlled yet. For example, we can't exclusively make nanotorii, only some of the batch are ring-shaped. Some day researchers will discover a way to make these rings by the trillion.... the challenge then is to figure out how to assemble them into chains.

Current state-of-the-art is a device called an Atomic Force Microscope that can directly image something as small as a nanotorus. There is also a device called a Nanomanipulator, which is like a force-feedback joystick, that can be used to nudge and move and assemble small numbers of these tiny rings. Chains are merely the simplest things that might be created from the nanotorus, there is also the classic chain maille that, even today, forms at lease one of the primary layers in every suit of body armor worn by law enforcement.

Here are some possible weaves and designs for nanotorii ::

How bout this 2:6 orbital Fullerene (shown inflated with a plastic bag)? This is very cool stuff.