Data storage

The nation's 115 million home computers are brimming over with personal treasures - millions of photographs, music of every genre, college papers, the great American novel and, of course, mountains of e-mail messages.

Yet no one has figured out how to preserve these electronic materials for the next decade, much less for the ages. Like junk e-mail, the problem of digital archiving, which seems straightforward, confounds even the experts.

Molten silicon, designer molecules, and protein globules from a cow. Someday, one of these materials could be used to store data in cell phones and PCs.

A number of start-ups are tinkering with technology that could enhance or replace hard drives, flash memory cards and other storage devices. The new technology will benefit consumers, but, just as important, reduce the onerous capital budgets facing manufacturers.

England's NanoMagnetics, for instance, has developed a method for inserting a magnetized particle inside a sphere of ferritin, a protein produced by animals. Assembled in arrays, the magnetized protein globs can be flipped to represent 1s and 0s, the basic units of digital information.

"I'll go to conferences and people will ask, 'This stuff is a protein. Can you eat it?'" said Eric Mayes, NanoMagnetics' founder and CEO.

On one level, the mission of these companies is a Pyrrhic quest. Hard-drive manufacturers regularly report financial losses and, until recently, profits in flash memory often proved elusive. Moreover, both industries are notoriously conservative when it comes to adopting new technologies.

Advocates, though, believe that circumstances that are transpiring will start to pry the door open to experimentation. For one thing, the cost-benefit equation for producers is getting extraordinarily steep. A gigabyte of hard-drive space currently sells for around 50 cents at retail outlets. Flash memory is also declining in price. Factories to build these devices, however, can cost billions, and research budgets can be arduous.

At the Semicon West conference in San Francisco in July, Paolo Gargini, director of technology strategy at Intel, noted that the chip industry has taken the first tentative steps toward adopting new manufacturing and design methods because of the cost and scientific difficulties that are ahead.

At the same time, advocates claim they can achieve far greater densities than is possible with existing technologies.

"I can see us doing 20 to 50 times the capacity per (chip) than they do," said Nanochip CEO Gordon Knight, referring to flash memory makers. His company is a Fremont, Calif.-based start-up that has received a rare venture investment from Microsoft.

Cranking up the heat
Heat is a problem for most semiconductor manufacturers, but it is the key to Nanochip's technology. A microscopic probe hovering above a piece of silicon quickly heats a point on the silicon to over 600 degrees Celsius. Almost instantly, the silicon crystal beneath the probe becomes amorphous, and thus gets read as a 0. When it cools, it crystallizes, and the area registers as a 1.

Using material this way to store data is part of the field of electronics called "Ovonics." The concept is similar to IBM's Millipede technology, but it relies on different processes to change the underlying media and uses fewer probes, Knight said.

New technology could soon overrun all the existing forms of memory used in computers, according to the company developing it.

Carbon nanotube memory could be a panacea to all existing memory issues, start-up Nantero said, because it was cheap and did not lose its contents if turned off. Currently computer memory comprises DRAM, S-RAM and NV-RAM (or flash memory).

DRAM, used in PCs and servers, is fast and cheap but its contents are lost when power is switched off. SRAM or Static RAM is faster and needs less power but is more expensive and also loses its contents when power is switched off. It is used most commonly for cache memory. NV-RAM is slower, power-hungry, very expensive but keeps its contents when power is switched off.

But Nanotube-based/Nonvolatile RAM (NRAM) could eventually replace all three. It is not without competitors though -- Phase-change memory and Magnetic RAM are also competing for the prize. So what's special about carbon nanotubes?

It's faster than SRAM, it should be cheap and it doesn't lose its contents when switched off. It should have an almost unlimited life, it should eventually be denser than DRAM, needs less power than DRAM and is resistant to radiation.

Nantero CEO, Greg Schmergel, claims carbon nanotube memory could be made with conventional CMOS manufacturing, keeping costs low. PCs using it could have an instant-on capability, no more lengthy boot time. Servers could have the speed of SRAM without the cost. Devices using flash could have greatly increased capacity for much lower cost. This would be nirvana for all of us and billionaire status for Nantero founders. How is it done?

Many materials lose their useful properties as soon as their dimensions fall below a certain limit. This so-called size effect, the sources of which may be quite diverse, can be a road block for the miniaturization of electronic, electromechanic, and electrooptic components. For a particularly promising class of materials, viz. the ferroelectric oxides, researchers from the Max Planck Institute of Microstructure Physics have now identified a new origin of the size effect: Tiny linear defects, with an extension of less than about a tenth of nanometer, are able to deform a tube of material with rectangular cross section of about 4 by 8 nanometer around them. This deformation is so severe that the useful ferroelectric properties of the material are destroyed within the tube. This new finding shows that the formation of these defects has to be avoided, if ferroelectric oxides of nanometer dimensions are to be used as memory elements in future electronic components.

Toshiba Corp. has developed what it believes is the smallest functional hard drive for next-generation cell phones and other portable gadgets — a nickel-sized disk that can store two to three gigabytes of music and video.

At 2 centimetres in diameter, the Toshiba drive would beat a 2.2-cm model from Hitachi Global Storage Technologies, Hitachi's U.S. unit. But the Hitachi drive stores 4 gigabytes. Hitachi refused to give shipment figures or other details.

The density of information stored on magnetic films has increased by a factor of 2 million since disk drives were introduced by IBM Corp. in 1957. Drives that store 70 Gbits/square inch are on the market now, and research projects have demonstrated densities three times as high. The dizzying pace, which outstrips the growth curve of silicon VLSI technology, has been sustained by fundamental materials research.

In the ongoing quest to create computing devices that are both incredibly small and incredibly powerful, scientists – envisioning a future beyond the limits of traditional semiconductors – have been working to use molecules for information storage and processing.

An atomic-scale memory chip, made by removing individual atoms from a silicon wafer, has been created by a team of scientists led by Franz Himpsel, professor of physics. The feat, reported in the journal Nanotechnology, represents a first crude step toward a practical atomic-scale memory where atoms of silicon would represent the binary 1s and 0s that computers use to store data.
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Two materials researchers have developed an extremely sensitive nanoscale device that could shrink ultra-high-density storage devices to record sizes. The magnetic sensor, made of nickel and only a few atoms in diameter, could increase data storage capacity by a factor of a thousand or more and could ultimately lead to supercomputing devices as small as a wristwatch. The National Science Foundation (NSF) supported the research.
As stored "bits" of data get smaller their magnetic field gets weaker, making the bits harder to detect and "read." Reliable reading of the data depends on producing a large enough magnetically-induced change in the electrical resistance of the sensor. Producing a detectable change at room temperature is another challenge.