The line between science and science fiction grew fuzzier last week when a team of researchers said they have taken a big step toward building a super small, super fast computer based on molecular, rather than silicon, chips.
Researchers from the University of California at Los Angeles and Hewlett-Packard Research Laboratories have found a way to fashion a "logic gate" -- a basic building block of all computers -- from a certain type of molecule. By attaching a few wires and switches, a group of the molecules can be knitted together to perform like a silicon chip, but on a molecular scale.
"We can potentially get the computational power of 100 workstations on the size of a grain of sand. We'll do it in steps; I'm hopeful that we can do it in about a decade," James Heath, the UCLA chemistry professor in change of the research team, said in a statement. The work is described in the latest issue of the journal Science.
The development could prove vital in helping to sustain the rapid pace of development that the computer industry has enjoyed in recent decades, the researchers said. Silicon chip technologies are expected to reach certain theoretical limits in the next 10 to 15 years, while chip plants are becoming prohibitively expensive to build.
Smaller than bacteria
Molecular computers could be built smaller and more cheaply than silicon allows, and would suck up much less power to operate, making them far more portable. The researchers say they hope to build entire memory chips that are a hundred nanometers wide -- smaller than a single bacterium.
"You can potentially do approximately 100 billion times better than a current Pentium in terms of the energy required to do a calculation," Heath said.
The researchers have dreamed up all sorts of possible applications for their molecular processors: supercomputers the size of wristwatches, computers that can be woven into clothing, biomedical instruments that can be injected into the human body to help diagnose diseases.
The team acknowledges that many hurdles stand between it and the first true molecular computer. Unlike the relatively exact science of silicon engineering, anything built using chemistry "inevitably has defects," Heath said. The team believes it can identify these defects and use wires and switches to route around them.
Prototypes of molecular-based computers may be only a few years away, and a hybrid computer combining molecular electronics with some silicon technology could follow in a decade, Heath said.
"Years ago, when I first told people I was trying to make a computer chemically, I wasn't taken very seriously. Although the idea is getting a little more respect now, we still have a long way to go," Heath said.