Scientists Soup Up Micro Speed Racer

May 9, 2008 -- Some people customize cars by adding fuel injection systems and extra strong alloys. Now scientists in Arizona have customized nanoengines by spiking the gas with rocket fuel and adding carbon nanotubes to strengthen the motor's micro-sized frame.

The new additions revved up the tiny motors to 20 times faster than existing nanomotors.

A nanomachine is a tiny device that is less than a micron (one millionth of a meter) in size that scientists hope to use in a variety of medical and research applications.

The Arizona team's powerful nanomotors could one day deliver disease-fighting drugs inside the body to invading pathogens or tumor cells or help clean up environmental toxins by using them as fuel.

"This is the first example of a powerful, man-made nanomotor," said Joseph Wang, director of the Biodesign Institute at Arizona State University and a coauthor on the study to appear in the May 27 issue of the American Chemical Society Nano.

The heart of this synthetic nanomotor is a tiny rod, tipped with gold on one end and platinum on the other, that has been around for years.

When the gold or platinum encounters the fuel, hydrogen peroxide (H2O2) or hydrazine (H2N4), the metal breaks up the fuels' molecules, releasing water and oxygen in what one researcher, Vincent Crespi, describes as a "little jet of water."

Crespi is a researcher at Penn State University who works on similar gold-platinum-based nanomotors but was not involved in the most recent article.

The key to speed, according to Wang, is the tiny electron that gets peeled off during the reaction and powers the reaction between the fuel and the gold-platinum rod.

Hydrogen peroxide is the same chemical that bleaches hair. Hydrazine is used as rocket fuel.

To the existing gold-platinum rod, the scientists in Arizona added carbon nanotubes, which had never been done before.