http://www.space.com/businesstechnology/technology/space_gear-1.html

Molecular Switch

Before any human sets foot on Mars our machines will be probing worlds far beyond. The first travelers beyond the solar system will be big, clunky probes, but those following in quick succession are getting smaller and smaller. Now Penn State and Rice University researchers backed by the Pentagon and industry investors have partially opened the way for microscopic explorers with electrical switches no bigger than a molecule.

Whether this is an inflationary universe -- filled with dark matter and dark energy, quintessence, virtual particles, and whatnot or not -- this is most definitely a binary universe for our computers. Every wonder is to be seen in ones or zeros – a yes or a no. On or off.

In the 22 June 2001 edition of Science, the team describes how it learned to bind molecules of one type into a tight matrix of another. The switching molecules were held tightly in such a way that when they’re electrically stimulated, they are forced to shift their shape in one direction only, rotating around one chemical bond. The result is a pronounced and predictable bulge. The phenomenon has been reported in sheets of molecules before, but the Penn State and Rice team was the first to confine and control the behavior within a single molecule.

The good news is that the switch can hold position for many hours, meaning information can be sustained for useful periods. The bad news, according to Penn State chemist Paul Weiss, is that while turning the switches off has been easy, "turning them on was more problematic. Clearly, we have an indication it can be done," Weiss said in a news release. "It's just a matter of setting up the experiment in the most efficient manner."

http://stm1.chem.psu.edu/

-- Erik Baard, Technology Correspondent