Researchers: Salt may improve hard drives' capacities

A common item like sodium chloride - table salt - can make computer hard drives cram data up to nearly six times their current capacities, Singapore researchers have found. Dr. Joel Yang of the Institute of Materials Research and Engineering (IMRE) said salt can be added to a developer solution to produce the bits that hold data. "The secret of the research lies in the use of an extremely high-resolution e-beam lithography process that produces super fine nano-sized structures. Dr. Yang discovered that by adding sodium chloride to a developer solution used in existing lithography processes, he was able to produce highly defined nanostructures down to 4.5 nm half pitch, without the need for expensive equipment upgrades," the Agency for Science, Technology and Research (A*STAR) said. It said Yang invented the "salty developer solution" when he was a graduate student at the Massachusetts Institute of Technology. The IMRE, a research institute of Singapore's A*STAR, worked with the National University of Singapore (NUS) and the Data Storage Institute (DSI) to develop a process that can increase the data recording density of hard disks to 3.3 terabit per square inch. In the research, scientists used nanopatterning to closely pack more of the miniature structures that hold information in the form of bits per unit area. With such technology, A*STAR said a hard disk drive that holds one terabyte of data today "could, in the future, hold 6 TB of information in the same size." Presently, hard disks have randomly distributed nanoscopic magnetic grains, with a few tens of grains used to form one bit, that allow the latest hard disk models to hold up to 0.5 terabit per square inch of data. Current technology uses tiny grains of about 7 to 8 nanometers in size deposited on the surface of storage media. Information or a single bit, is stored in a cluster of these grains and not in any single grain. But the IMRE-led team used the bit-patterned media approach, where magnetic islands are patterned in a regular fashion, with each single island able to store one bit of information. IMRE’s bits are about 10nm in size but store information in a single structure. Such a method could ramp up data-storage capability to 1.9 Terabit per square inch, though bits of up to 3.3 Terabit per square inch densities were fabricated. “What we have shown is that bits can be patterned more densely together by reducing the number of processing steps," said Yang. “In addition to making the bits, we demonstrated that they can be used to store data," he added. Researchers are now looking at increasing the storage density further. A separate article on Computerworld said the new technology would theoretically allow more than 21TB of data on a single drive. Today's NAND flash-based solid-state drives use lithography processes that create circuitry about 25nm in width; a human hair is 3,000 times thicker than 25nm. — LBG, GMA News