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New Polymer Ideal For Secure Data Storage
aphexbrett writes "Clever geometry is the basis of a new material that is said to be ideal for secure data encryption and dense optical information storage. The material consists of a lattice of onionlike spheres in which the particle core and its layers each contain a different dye. The material can hold four or more pieces of information in one spot--not just two as in binary optical data storage. And it opens a door to high-density three-dimensional optical data storage. Read a summary of the research over at C&EN News."
This process is not very useful for the proprosed applications of data storage. The main hurdle in that case is dynamic, accurate access to setting flags one way or another and then subsequently reading them. This is nothing more than a way to trap molecules in concentric shells of layers of polymer, a far cry from high performance data storage. Don't hold your breath yet.
the article doesn't seem to mention how robust such a material would be - will the dyes last for a long period of time, and if not, will some dyes fade before others?
Given the correct photo-stabilisers, the dye layers could be made to last for "extended" periods of time. Maybe up to years? The problem lies with the light-fastness of dyes; when a dye molecule undergoes the electronic interaction with light that produces colour there is a % chance that the molecule will be damaged by that change. The higher the energy of the electronic interaction, the higher the % chance of damage.
Blue (visible) dyes are generally amongst the most intrinsically stable as their interactions are with the red (low energy) portion of the visible spectrum. On the other hand, UV reactive dyes (such as Optical Brighteners/Flourescent Whiteners) are degraded very quickly by their high energy interactions. Put a sheet of copier paper out in the sun for a couple of days, and then hold it next to a new sheet - you'll see how quickly the OBA's have been destroyed!
Now, photo-stabilisers can be added to the dye mix to counteract these degredation processes but in a system where you are wanting several dyes to be active at differing wavelengths it will be difficult in the extreme to arrange the system so that one of these "onion layers" doesn't absorb the wavelength required by another layer!
Finally, making a reader for the material is one thing
And what a thing it would be! The nice thing about silicon chips is that the access time is constant (IIRC each bit is activated in parallel?) across the storage unit. You can read bits 1, 2 and then 3 with the same latency as bits 1, 1583945856 and then 393758273589235892253. With a "three dimensional matrix" of discrete units, you first have to find your bit before it can be read! Imagine with current mass-use technology... a read head housing 4 lasers (as in the 4 dye example in the article) trying to access a bit at the "start" of the data, then one that's physically 1.5cm away, and then again, and again, and again.... the latency would be huge!! Maybe I don't know enough about
So yes, security tagging would be OK - relying on the macro-structure of the matrix under different lighting and the good old Human Eyeball Mk1 - but data storage? I think it'll be a while before this gets used...