In the future, ultra-high-density non-volatile storage — such as hard drives — could be grown using magnetic bacteria.

This breakthrough, shepherded by researchers from the University of Leeds in the UK and the Tokyo University of Agriculture and Technology, relies on certain strains of bacteria that ingest iron, which is then converted into magnetite (iron II, III oxide), the most magnetic naturally occurring mineral on Earth. These microbes, by following the Earth’s magnetic field, use this built-in magnet to navigate.

To turn this behavior into something that can actually act as magnetic storage, the researchers identified and extracted the protein responsible for converting iron into magnetite — Mms6. A gold substrate is then covered in a checkerboard fashion with chemicals that bind to Mms6, and the substrate is dunked in the protein. The whole caboodle is then washed with an iron solution, turning each of the Mms6 sites into a magnetic bit (pictured above)

For now the researchers have only managed to create magnetic bits that are 20 micrometers wide, which equates to 20,000 nanometers — a wee bit larger than the 10nm magnetic sites found on modern hard drives. Speaking to New Scientist, though, Sarah Staniland, the lead researcher, seems confident that a checkerboard of 20nm magnetic sites should be possible. Ultimately, Staniland wants to refine the process so that there’s just one magnetite molecule per bit, which equates to around eight terabits (1TB) per square inch. This is comparable to Seagate’s HAMR hard drive technology, but I suspect Staniland has no idea whether her one-molecule-per-bit platters will be read/writable by conventional hard drive heads.

Ultimately, though, the real appeal here is that we might eventually be able to grow non-volatile storage, rather than manufacture it. Imagine if your computer had a hard drive that simply grew another platter when it approached capacity; imagine if repartitioning a hard drive actually split your hard drive platter into multiple fragments, which could then be re-grown to become complete platters. We should also bear in mind that quite a lot of money is being spent on researching biological computers; devices that use chemical reactions to perform calculations. We have already seen a biological computer that uses DNA to store small amounts of data, and computer memory made out of salmon DNA (pictured right) — maybe Staniland’s discovery could become the basis of a biological mass storage device.

Read more at University of Leeds