Tailoring carbon nanotubes
We have harnessed the atomically smooth, nested structure of a multiwalled carbon nanotube to create the world's smallest synthetic rotational motor. Unlike existing chemically driven bio-motors, our nanometer-scale electromechanical system (NEMS) actuator is designed to operate over a wide range of frequency, temperature, and environmental conditions, including high vacuum and harsh chemical environments.
After depositing multiwalled nanotubes on a silicon oxide surface, anchors and rotors made out of gold are attached to the nanotubes using electron beam lithography. Stator electrodes are placed on either side of each rotor to provide a mechanism to drive the rotor. Once these features are in place, the underlying silicon oxide is partially etched away to suspend the rotor and nanotube assembly. Finally, the outer nanotube wall is severed on either side of the rotor to allow the center section to spin freely.
Winner of the 2004 R&D 100 Award!