Scientists have built a memory chip that is about the size of a white blood cell: about one-2,000th of an inch on a side.
Although the chip is modest in capacity -- with 160,000 bits of information -- the bits are crammed together so tightly that it is the densest ever made. The achievement points to a possible path toward continuing the exponential growth of computing power even after current silicon chip-making technology hits fundamental limits in 10 to 20 years.
The scientists, led by Dr. James Heath of the California Institute of Technology and Dr. J. Fraser Stoddart of the University of California, Los Angeles, will report their findings in today's issue of the journal Nature. As far back as 1999, Heath and Stoddart reported on aspects of their work, which included specially designed molecular switches and a novel technique for making ultrathin wires. The new work pulls the components into an integrated circuit.
"Our goal always was to develop a manufacturing technique that works at the molecular scale," said Heath, a professor of chemistry. "It's a scientific demonstration, but it's a sort of a stake in the ground."
The density of bits on the chip -- about 100 billion per square centimeter -- is about 40 times as much as current memory chips, Heath said. Improvements to the technique could increase the density by a factor of 10, he said.
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But Heath said he did not know if this technique would be commercially useful. "I don't know if the world needs memory like this," he said. "I do know if you can manufacture at these dimensions, it's a fundamentally enabling capability."
For example, the wires used in the chip are about the same width as proteins, and that could make possible tiny circuits that could detect cancer or other diseases.
