Wednesday, January 24, 2007

Ultradense Molecular Memory

Continued from page 1

By Kevin Bullis

Heath and his colleagues at Caltech then developed techniques for incorporating these molecules into a memory chip. Taking advantage of the fact that one end of the molecules is attracted to water while the other end is repelled by it, the researchers were able to arrange the molecules so that they were all oriented in the same direction in a layer just one molecule thick.

Much work remains to be done before the method can be useful for practical electronics. Of the bits tested in the device, nearly 75 percent didn't work for a variety of different reasons. Furthermore, those that did work could only be switched a few times before failing.

Still, experts say the current work is already an important step forward for molecular electronics. Although molecules and nanowires still can't compete with the manufacturability of silicon chips, the new work "takes molecular electronics to the next level," says James Tour, professor of chemistry and computer science at Rice University. To achieve such densities in the memory devices, he adds, is "impressive."