BY SEBASTIAN ANTHONY
Running out of storage space? Thanks to engineers at Florida International University (FIU), hard drives with 100TB or more of storage space could be on the horizon. Most magnetic storage breakthroughs have been fundamentally 2D in their implementation, and thus are ultimately restricted by superparamagnetic limits: Magnetic bits can only be so small before neighboring bits or changes in temperature can randomly alter the magnetism. Therefore, the only solution is to move beyond simple improvements—and into the third dimension.
The FIU researchers have created a new hard drive platter that allows for the writing and reading of 3D magnetic data. In essence, instead of having just one magnetic layer, the new platter has three, with isolation (insulation) layers sandwiched in between. On a conventional hard drive platter, a magnetic site stores just a single bit of data; here, each magnetic site can store up to eight (north/north/north, south/south/south, N/N/S, N/S/S, and so on).
To read data, a weakly magnetic head measures the vector sum of the three magnetic fields. To write data, each layer of the recording medium has slightly different properties, so that they can only be written by a specific type and strength of magnetic field, which is output by a special recording head. For now, FIU’s new magnetic recording medium is an in-the-lab tech demo. Whereas conventional hard drive platters are mass-produced using a simple process called magnetron sputtering, FIU’s platter is more like a small disc of silicon that goes through dozens of painstaking processes, including e-beam lithographic patterning. This isn’t to say that multilayer 3D (ML-3D) recording won’t become a reality, but alternatives such as heat-assisted magnetic recording are much closer to commercial adoption. That ML-3D might be used to create 100TB or larger hard drives in the future, though, is still exciting news—and, interestingly, perhaps the technology that will finally kill off the magnetic tape, which is still hanging in there as the preferred bulk offline storage medium.
