April 13, 2006, Houston, TX--In follow-on work to last year's invention of a single-molecule car, chemists at Rice University have produced the first motorized nanocar. The vehicles, described in today's issue of Organic Letters, are test transport systems that may one day deliver molecular cargo for nanoscale construction. The car's light-powered motor rotates in one direction, pushing the car along like a paddlewheel.
"We want to construct things from the bottom up, one molecule at a time, in much the same way that biological cells use enzymes to assemble proteins and
other supermolecules," said lead researcher James M. Tour. "Everything that's produced through biology from the tallest redwood to largest whale is built one molecule at a time. Nanocars and other synthetic transporters may prove to be a suitable alternative for bottom-up systems where biological methods aren't practical."
The nanocar consists of a rigid chassis and four alkyne axles that spin freely and swivel independently of one another. The four buckyball wheels that were used in the original version of the nanocar drained energy from the motor and were replaced with spherical molecules of carbon, hydrogen and boron called p-carborane.
Initial tests carried out in a bath of toluene solvent found that the motor rotates as designed when it's struck by light. Follow-up tests are underway to determine whether the motorized car can be driven across a flat surface.
The nanocars, which measure just 3-by-4 nanometers, are about the same width as a strand of DNA, but much shorter than DNA. About 20,000 of these nanocars could be parked, side-by-side, across the diameter of human hair. They are the first nanoscale vehicles with an internal motor.