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The nanocar is a molecule designed in 2005 at Rice University in the group of Professor James Tour. Despite the name, the original nanocar does not contain a molecular motor, hence, it is not really a car. Rather, it was designed to solve the question of how fullerenes move about on metal surfaces; specifically, whether they roll or slide.
The molecule consists of a H-shaped 'chassis' with fullerene groups attached at the four corners to act as wheels.
When dispersed on a gold surface, the molecules attach themselves to the surface via their fullerene groups and are detected via scanning tunneling microscopy. One can deduce their orientation as the frame is a little shorter than its width.
Upon heating the surface to 200 °C the molecules move forward and back as they roll on their fullerene "wheels". The nanocar is able to roll about due to the fact that the fullerene wheel is fitted to the alkyne "axle" through a carbon-carbon single bond. The hydrogen on the neighboring carbon is no great obstacle to free rotation. When the temperature is high enough, the four carbon-carbon bonds rotate and the car rolls about. Occasionally the direction of movement changes as the molecule pivots. The rolling action was confirmed by Professor Kevin Kelly, also at Rice, by pulling the molecule with the tip of the STM microscope.
Although the current research has no immediate applications, Professor Kevin F. Kelly suggested in an interview  that the knowledge gained from the nanocar research might help build more efficient catalytic systems in the future.
Independent early conceptual contribution
Rice University group of Prof Tour is an undisputed leader in realization of "nanocar" artifacts, however the concept of a nanocar built out of molecular "tinkertoys" was first hypothesized by Marek T. Michalewicz at The Fifth Foresight Conference on Molecular Nanotechnology, Palo Alto (1997 Nov 5-8) . Subsequently an expanded version was published in Annals of Improbable Research, Vol. IV, No. 3 March/April 1998 . These papers supposed to be a not-so-serious contribution to a fundamental debate on the limits of bottom-up Drexlerian nanotechnology and conceptual limits of how far mechanistic analogies advanced by Eric Drexler could be carried out. The important feature of this nanocar concept was the fact that all molecular component tinkertoys were known and synthetized molecules (alas some very exotic and only recently discovered, e.g. staffenes, and notably - ferric wheel, 1995), in contrast to some Drexlerian diamonoid structures that were only postulated and never synthesized; and the drive system that was embedded in a ferric wheel and driven by inhomogeneous or time-dependent magnetic field of a substrate - an "engine in a wheel" concept.
A future nanocar with a Synthetic molecular motor has been developed by Jean-Francois Morin et al. "En route to a motorised nanocar" Abstract. It is fitted with carborane wheels and a light powered helicene synthetic molecular motor. Although the motor moiety displayed unidirectional rotation in solution, light-driven motion on a surface has yet to be observed. Motility in water and other liquids can be also realized by a molecular propeller in the future.
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Nanocar". A list of authors is available in Wikipedia.|