Nobody likes a mess, even a microscopic one. For one thing, it´s tough to clean what you can´t see. That´s why researchers at Rensselaer Polytechnic Institute are crafting the world´s smallest brooms. The tiny tools are made by growing bristles of superstrong carbon nanotubes on a silicon-carbide fiber just 16 microns in diameter, or about half as thick as a human hair. Scientists create the "handle" by coating one end of the fiber with gold, which inhibits nanotube growth.