Artificial molecular rotors

An overview of the current state of artificial molecular rotors is presented. Both molecular rotors exhibiting thermally induced rotation and those designed so as to be capable of being driven by an external force, such as an electric field or flow of a fluid, are considered. The breadth of the subject ranges from preparative chemistry to theoretical physics, as well as fundamental to application-oriented studies. Some of the current challenges are also covered including, a demonstration of coherent motion in regular arrays of dipolar rotors, demonstration of advanced methods for driving unidirectional rotation, realization of structures that minimize rotational energy dissipation by friction, and demonstration of fluid flow-rotor interactions, initially with flow-driven rotors and ultimately perhaps with rotor-driven flow.