A technique that enables the nanopatterned layers that store data in hard disk drives to assemble themselves has been improved to better suit mass production, and could enable disks that store five times as much data as the largest available today.

Using self-assembly instead of machines that print or etch out features has long been considered a potential solution to a looming barrier to expanding the capacity of hard-disk designs. Researchers at the University of Texas at Austin have now worked out a solution to a problem that made self-assembly incompatible with existing factories.

Hard disks store data on a spinning disk, written into a pattern of magnetized regions on a magnetic coating. For decades, gains in hard-drive capacity have come from packing those regions—and hence data—more densely. But now they can’t be positioned much closer together without magnetic interference endangering the reliability of data storage.