12 June 2002
could store one terabit of data
18:20 11 June 02
NewScientist.com news service
A way of storing a terabit of data on a chip no bigger than a postage stamp has been developed by researchers at IBM.
The Millipede chip, created by a team in Zurich, Switzerland, stores single bits of data in the form of tiny indentations.
The indentations are made in the surface of the chip using tiny "spikes" or tips on the end of pivoting arms. These same spikes are used to write, read and erase data on the chip.
So far, the researchers have created a prototype chip with 1024 arms, creating indentations 40 nanometres across, giving a storage capacity of 200 gigabits per square inch. But they have demonstrated with a one-arm chip that they can make the indentations smaller - potentially increasing the capacity to one terabit.
This is 10 to 15 times more than would be possible with existing proven chip technology. One terabit is equivalent to the information stored on 200 CDs.
"This technology has very strong potential for application in handheld and mobile devices," Peter Vettinger, Millipede project leader, told New Scientist.
The technology could massively increase the capacity of an MP3 player, for example.
Heating and cooling
The surface of the chip consists of a layer of plexiglass on top of silicon. "Writing" data involves heating a tip to 400°C, which enables it to make an indentation in the surface.
To erase data, the tips apply heat to the edges of the indentations, smoothing the surface.
To read the chip, the temperature of the tip is reduced to 300°C. As the tip runs over an indentation it cools further - and that change in temperature is measured.
"Since a nanometre-scale tip can address individual atoms, we anticipate further improvements far beyond even this fantastic terabit milestone," said Gerd Binnig, one of the developers of the Millipede technology.
The researchers admit that the technology is a number of years away from being ready for practical applications. But they plan to build a prototype chip with 4096 tips early in 2003. This would allow the chip to read and write data much faster. The research will appear in the IEEE journal Transactions on Nanotechnology.