Salt has served as the foundation for cuisines worldwide and supported the rise of empires throughout human history. Now it represents the special ingredient for creating new computer hard disk drives capable of storing six times more data than existing hard drives.
Singaporean researchers found that sodium chloride, the formula for table salt, can act as the chemical key for making denser hard drives with "bits" of information stored in single tiny structures. Their breakthrough means that hard drives capable of holding just 1 terabyte of data could someday hold 6 terabytes — about enough music to play continuously for 12 years straight.
"What we have shown is that bits can be patterned more densely together by reducing the number of processing steps," said Joel Yang, a scientist at the Institute of Materials Research and Engineering in Singapore. "In addition to making the bits, we demonstrated that they can be used to store data."
Existing hard disk technology can only store bits in a cluster of tiny "grains" stuck on the surface of storage material; each grain measures smaller than most viruses at 7-8 nanometers in size. By contrast, Yang's team showed how to store information in just a single grain about 10 nanometers in size, without needing a cluster of such grains.
The researchers used a beam of electrons to trace the shape of tiny nanostructure patterns in a film covering the surface of the storage device. They then used a "salty developer solution" to wash away the parts of the film affected by the electrons, leaving behind the desired pattern.
For now, the technique has led to demonstrations of data-storage capability at 1.9 terabits per square inch (1 terabyte is equivalent to 8 terabits). But researchers also created densities equivalent to 3.3 terabits per square inch, and plan to further improve such information density to meet future computing needs.