The magnetic spots in disk storage are already smaller than semiconductor feature sizes, and patterned media and heat-assisted recording will give us 10 TB 2.5″ disks in the next decade. But then what? Optical protein-based quantum dots could be the answer.

Scientists at a Osaka University lab say in a recent paper:

. . . we have established a novel, rapid method for the fabrication of a “protein recording material”, which enables us to spatiotemporally regulate the recording, reading, and erasing of a fluorescent protein array as information by a photochemical technique. A photolinker that we synthesized here was used to control the protein array spatiotemporally.

The patterned surface was manufactured using two similar processes. One used quantum dot 605-streptavidin conjugates. Under a medium wave UVB laser, the conjugate fluoresces, distinguishing a 1 from a zero. They used a similar substance to build a positive version as well.

The team
Professors Koji Nakayama, Takashi Tachikawa, and Tetsuro Majima, who authored the paper have published an incredible amount of work on nanotechnology, biochemistry and chemistry. It feels like they woke up one day and realized, “hey, we have fluorescent markers, proteins and substrates, let’s build a storage prototype!”

Here’s a picture I borrowed from their paper:

Mainstream technology
What I like about this technology – and this is simply a lab demo, nowhere near commercial introduction, and could be derailed by many problems – is that it could use much of today’s disk infrastructure. Servo, signal processing, steppers, glass disks – and some of the planned future technology – patterned media and HAMR lasers – is directly applicable.

The underlying technology is widely used, as the team notes:

Protein patterning on solid surfaces is a topic of significant importance in the fields of biosensors, diagnostic assays, cell adhesion technologies, and biochip microarrays.

The importance of utilizing existing technology, representing thousands of man-years of refinement and billions of dollars of investment, is key. Thousands of engineers know how to work with current technology, speeding adaptation of new techniques.

The Storage Bits take
Few appreciate how much the exponential increase in storage areal density has fostered computing advances. As Moore’s law has driven processing power, the advance of storage technology has – just barely – enabled massive data stores and rates to feed insatiable processors.

Optical protein storage should be much more stable than magnetic storage as well. Magnetic bits are subject to many kinds of degradation, while proteins can be very persistent, as the prions causing Mad Cow disease show.

Much work remains before protein storage sees the light of a commercial introduction. Its importance is that it gives us another tool to advance our ability to preserve and access the information that makes our culture and civilization possible. Professor Tetsuro Majima and his team deserve our gratitude for this breakthrough.

Comments welcome, as always. This is a highly technical chemistry paper so I just skimmed the surface. Get the pdf here.