Researchers have simulated attaching benzyne molecules to the outside of a nanotube to form gear teeth, explained Globus.
Nanotubes are molecular-sized pipes made of carbon atoms.
You also need a cooling system for gears. The laser creates an electric field around the nanotube. We put a positively charged atom on one side of the nanotube, and a negatively charged atom on the other side. The gears that Globus and others have simulated with computers would be about a nanometer across. A nanometer is one-billionth of a meter.