The breakthrough could give researchers an efficient way to control the flow of information on such minuscule circuits — a requirement if tiny but enormously powerful molecular computers are ever to become a reality.

Researchers in the burgeoning field of nanotechnology hope to someday create computers small enough to be sprinkled like dust, embedded in materials or perhaps even injected into the bloodstream to serve as diagnostic sensors.

The Hewlett-Packard-UCLA team, which is partly funded by the US Defence Department, already has patented a way to connect molecularscale switches with chemical "wires" that are just six to 10 atoms wide and two atoms tall about one hundredth the size of the tiniest wires on chips.

Last year, R Stanley Williams of HP and Philip Kuekes and James Health of UCLA developed a chemical process and computer program that would allow the circuitry to be mapped like perpendicular city streets. In that way, a computer’s central processing unit could know exactly where on the molecular grid certain information was being stored.

But simply providing routes for electrical impulses to travel is not enough. For a molecular circuit to really work, researchers need to have a way of managing the way the signals travel.

So to govern their small city, the HP-UCLA team proposed creating a rough equivalent of traffic lights. It was that electric-chemical process that won a patent in November.

"I believe that in 10 years we definitely will have hybrid molecular-silicon circuitry," Williams said.