1. Department of Physics, University of California at Berkeley, and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
2. Present addresses: Department of Physics, University of Maryland, College Park, Maryland 20742-4111, USA (M.S.F.); Department of Physics, Stanford University, Stanford, California 94305-4045, USA (J.C.).

Correspondence to: A. Zettl¹ Correspondence and requests for materials should be addressed to A.Z. (Email: azettl@physics.berkeley.edu).

Nanostructures are of great interest not only for their basic scientific richness, but also because they have the potential to revolutionize critical technologies. The miniaturization of electronic devices over the past century has profoundly affected human communication, computation, manufacturing and transportation systems. True molecular-scale electronic devices are now emerging that set the stage for future integrated nanoelectronics¹. Recently, there have been dramatic parallel advances in the miniaturization of mechanical and electromechanical devices². Commercial microelectromechanical systems now reach the submillimetre to micrometre size scale, and there is intense interest in the creation of next-generation synthetic nanometre-scale electromechanical systems^{3, 4}. We report on the construction and successful operation of a fully synthetic nanoscale electromechanical actuator incorporating a rotatable metal plate, with a multi-walled carbon nanotube serving as the key motion-enabling element.