Mannerisms

"The shuttle memory has information density as high as one trillion bits per square inch and thermodynamic stability in excess of one billion years," says project leader Alex Zettl.

The memory that can last for a billion years consists of a crystalline iron nanoparticle shuttle enclosed within the hollow of a multiwalled carbon nanotube.

"We've created a memory device that features both ultra-high density and ultra-long lifetimes, and that can be written to and read from using the conventional voltages already available in digital electronics," says Zettl.

Low voltage current shuttles the iron back and forth inside the nanotube "with remarkable precision", said Berkley, and the shuttle's position can be read out directly as electrical resistance, allowing "potentially hundreds of binary memory states".

'In laboratory tests, this device met all the essential requirements for digital memory storage including the ability to overwrite old data', said Berkeley.

The Berkeley memory appears to have the potential to beat the endurance record for memory techniques.

Zettl pointed out that stone carvings in the Egyptian temple of Karnak store approximately two bits of data per square inch and can be read after nearly 4,000 years.