PALO ALTO, Calif. -- Hewlett-Packard Co. said today that it has just received a patent that may have eliminated a major obstacle to building a molecular-scale computer.
The patent, issued earlier in July by the U.S. Patent Office to HP Labs scientists Phil Kuekes and Stan Williams, comes up with a way to solve the problem of connecting molecular-scale devices to today's much larger integrated circuits.
"We have a strategy to reinvent the integrated circuit with molecular rather than semiconductor components," pointed out Williams, who is director of quantum science research at HP Labs. "We've received two key patents and have several more pending that we believe will eventually enable computers to be millions of times more efficient than they are today."
HP's roadmap calls for molecular electronics, which it regards as a brand new technology, to augment silicon-based integrated circuits within the decade and eventually replace traditional solid-state memories. Most experts believe that silicon technology will reach its key physical and economic limits by about 2012.
"The question is-once you've built a circuit from molecular-scale devices-- something about the size of a bacterium -- the question is how you get data into and out of it," said Kuekes, senior scientist at HP Labs. "To that, you have to bridge the size gap between current technology, which is a hundred times bigger, and molecular-scale wires and devices, which are about the size of a bacterium."
Since it would be just about impossible to make precise connections between molecular-scale wires and today's ICs, the new patent proposes making connections randomly using a chemical process.
"We've essentially created a city of streets crossed by avenues, but they're so tiny we can't paint the street signs," Kuekes said. "Instead, we have come up with a chemical process that gives each street and avenue a unique name. Then we run a program that identifies all the thoroughfares by their names and enables us to create a map of the city. Once you have that map," he says, "you can store and retrieve information at any intersection."
The new patent builds on one awarded in October 2000 that described a method for building a memory device from switchable molecules sandwiched between grids of nanometer-scale wires. HP and its partner in this work, the University of California at Los Angeles, also have demonstrated that molecular-scale electronic switches and the wires to connect them-"nanowires" that are 6 to 10 atoms wide and 2 atoms tall-can actually be made.
Researchers from the two organizations are now working on fabricating circuits from these components.
HP and UCLA expect to be able to fabricate a 16-kilobit memory using this approach by 2005. The work is being funded by a four-year, $12.5 million grant from the U.S. Defense Advanced Research Projects Agency and a $13.2 million investment from HP.
