August 28, 2007 |
Rewritable Holographic Memory for better data storage is hardly at the point, some already try to make it rewriteable, like CD and DVD RW. But here, the researchers use… proteins of bacteria!
To store data in a gel soaked with proteins: team of the research center in Nanobionics succeeded , at the university of Connecticut. The recording takes the form of a hologram and is thus spread out in three dimensions, reaching a high density. The first holographic-memory systems have recently come to market, but they do not yet feature discs rewritable in real time.
Researchers at the University of Connecticut, Storrs, led by
Jeffrey Stuart,, head of the Nanobionics Research Center at the university’s Institute of Materials Science, based their holographic storage system on reengineered versions of proteins produced by bacteria-like organisms commonly found in salt marshes. Simply shining blue light on the proteins erases any data stored in them
These two ideas – the holographic recording and the use of a protein – are neither one nor the other an innovation. The hologram is presented like the principle of the next generation of storage, which will come to replace the DVD. Known for a long time, it consists in solidifying in a transparent material support the interference rings created by the interaction between two luminous rays (in theory of the lasers). One is used as reference while other was modulated and is thus carrying information. For the reading, one clarifies the substrate with the ray of reference. After having crossed the traces of the interference, the light arises with the initial modulation: stored information is found.
A protein overcome by the light
As for proteins produced by bacteria-like organisms, a molecule able to transform the light into energy, like salt marshes. Certain micro-organisms close to the bacteria, pertaining to the group of states, can manufacture it and install it in their membrane. It is the case in particular of Halobacterium salinarum, which likes to live in the extremely salted environments. When oxygen has suddenly missed, this protein collects the light and changes to produce protons which will be used for the chemical machinery states. Chlorophyll functions in the same way. Once the released proton, the
bacteriorhodopsin, turns over in its initial state, collects a little luminous energy again and the cycle starts again.
For a few years, this protein sensitive to the light has attracted covetousness’s of the researchers who see in it a possibility of recording information. But the protein is not easily let tame: its cycle hard between 10 and 20 milliseconds and never stops. To store data, the scientists would like to obtain a stable state. They had already reached that point with a red flash of light.
protein is then blocked and becomes insensitive with the light. But this waving of a magic wand functions only when the protein is in a particular state, the state “Q”. Alas, this form does not form part of the usual cycle and it is thus not easy to obtain protein in this state by extracting it from the micro-organisms. …
Called with the rescue, of the geneticists arrangedHalobacterium
salinarum genetically modified which produces more bacteriorhodopsin with the state Q. It is it that Jeffrey Stuart and his colleagues of the university of Connecticut included in a gel. The light (laser) then makes it change form. This new state is stable him too. A blow of light of another color and the protein returns to the state Q. One can thus record one 0 or one 1. In the thickness of freezing, transparency, it is easy to work in three dimensions and one can obtain a hologram.
Very advanced, this work already starts to leave the laboratory. A company, Starzent, have been just created by the DARPA (Defense Advanced Research Projects Agency) to construct a prototype industrial sable. Tim Harvey, his president, ensures that this holographic memory with proteins can be rewritten ten million times and account on the biologists to manufacture a sufficient quantity of bacteriorhodopsin by arches genetically modified. One will obtain the first memory GMO then…