 Nanotube composite motor brushes are better-lubricated (from the matrix), cooler-running (both from better lubrication and superior thermal conductivity), less brittle (more matrix, and fiber reinforcement), stronger and more accurately moldable (more matrix).Since brushes are a critical failure point in electric motors, and also don't need much material, they became economical before almost any other application.Wires for carrying electric current may be fabricated from nanotubes and nanotube-polymer composites.