Table salt increase hard drive storage

Scanning electron microscopy images of magnetic bits at densities of (a) 1.9 Terabit/in² and (b) 3.3 Terabit/in². Image courtesy Singapore Institute of Materials Research and Engineering.

Researchers have developed a new process to increase the storage density of hard drive disks by six times thanks to a key ingredient – salt.

The work was done by a collaboration of Singapore research centers that included the Institute of Materials Research and Engineering, part of the Agency for Science, Technology and Research (A*STAR).

The team used a technique called ‘nanopatterning’ to pack together more of the tiny structures that hold information in the form of bits. These structures are comprised of closer uniform arrays of magnetic bits or ‘islands’.

“It’s like packing your clothes in your suitcase: the neater you pack them, the more you can carry,” said the A*STAR researchers, in a press release.

To make the denser data islands, sodium chloride or salt was added to a solution that was used by a very high-resolution e-beam lithography process to create super-fine nano-sized structures. This ‘salty solution’ was invented by Yang when he was a student at the Massachusetts Institute of Technology, in Boston.

Modern hard drive disks have randomly distributed nanoscopic (at a scale of a billionth of a meter) magnetic grains, with a few tens of them making one bit. This equates to 0.5 terabit per in² of data.

To increase hard drive storage capacity, the researchers used nanopatterning to organize these ‘magnetic islands’ in a regular instead of random manner. Each island can store one bit of information and up to six times the recording density of current devices. 

The result was a storage capacity of 3.3 Terabit per in², meaning a hard drive that can hold 1 terabyte (TB) of data today, could soon hold 6 TB of information, in the same amount of space and using the same technology. This new process was done without the need of expensive equipment upgrades.

“What we have shown is that bits can be patterned more densely together by reducing the number of processing steps," said Joel Yang, head of the project from the Institute of Materials Research and Engineering.

- Adrian Giordani