Self-assembling molecules may be the key to increasing hard drive densities into the next decade. Hitachi Global Storage Technologies, now owned by Western Digital, has announced a milestone in the development of storage media using a mix of self-assembling molecules and nanolithography. The two technologies were combined to form a "dense patterns of magnetic islands" only 10 nanometers wide. Those individual islands measure only 50 atoms across, and they enable a storage density of 1.2 trillion bits per square inch—double what's available in current HDDs. The official press release describes how the process works:
Self-assembling molecules use hybrid polymers, called block copolymers, composed of segments that repel each other. Coated as a thin film on a properly prepared surface, the segments line up into perfect rows. The size of the polymer segments determines the row spacing. After polymer patterns are created, a chip-industry process called line doubling makes the tiny features even smaller, creating two separate lines where one existed before. The patterns are then converted into templates for nanoimprinting, a precision stamping process that transfers the nanometer-scale pattern onto a chip or disk substrate.
Getting the patterns to form a radial path appropriate for rotating drive media proved particularly challenging for HGST and partner Molecular Imprints Inc. HGST says they're the "first to combine self-assembling molecules, line doubling and nanoimprinting to make rectangular features as small as 10 nanometers in such a circular arrangement." The read/write retention of the media is purportedly excellent, but the nanoimprinting tech hasn't been used to fill a full disk platter just yet.
Because it relies on bit-patterened media, storage is supposedly a good candidate for self-assembling molecules. Indeed, HGST Fellow Tom Albrecht believes even smaller dimensions are possible. The process is expected to be a cost-effective way to improve hard drive storage densities by the end of the decade.
Although SSDs are preferred for high-performance PC storage, they won't compete with the bit densities of hard drives anytime soon. Our thirst for local storage seems unlikely to wane even as the availability of online storage continues to expand, and high-density drives will be needed to host the bits for both. Self-assembling media is still far from commercialization, but we may soon get a boost in storage density from heat-assisted magnetic recording, otherwise known as HAMR. Complete with built-in frickin' lasers, HAMR-equipped drives appear to be on track to enable higher drive capacities as early as 2014.