As our internet use increases annually worldwide, so does our need for date storage capacity. “If we continue at this rate, we will need about 2,000 billion hard disks in the year 2040,” says Roeland Nolte, professor of molecular nanotechnology at Radboud University, “but we will never have enough silicon to make them. Moreover, data centres already consume more energy than the whole of Great Britain does in a year.”
We therefore need new forms of low-energy, efficient data storage. “It will take 10 to 20 years for the technologies that we currently develop to be implemented, which is why we need to start working on them now,” says Nolte.
Anticlockwise or clockwise, zero or one
Using a subsidy from the European Research Council, researchers at Radboud University are working on a promising and cheap form of date storage on long synthetic threads. “Polymers, which are repeating chains of molecules, have many advantages; for example, they are stable and you can make whatever you want from them.” Co-researcher and nanochemist Hans Elemans believes that it will be possible to store all the data in the world on a single car tyre using this technology.
Although scientists are already working on storing information on DNA chains (natural polymers), storage on artificial polymers has not yet been achieved. To do this, the researchers are working on inserting oxygen atoms into the chains in the form of ‘epoxide molecules’, using two different bond orientations: anticlockwise or clockwise, or a zero or a one. They are using their own molecular machine as a read/write head. The research group has already shown that this technique works and that it is fast. The problem, however, was the lack of control of the read/write head, as it produced a chaos of zeros and ones.
The read/write head moves along the long molecule chain (polymer) and binds oxygen atoms to the polymer in the form of a clockwise or anticlockwise epoxide bond (red and blue balls). This can be seen as writing zeros or ones onto the chain, in the same way as a hard disk stores information.
Molecular machine
After some tinkering with the read/write head, the researchers have now managed to assign a preference to the head: clockwise or anticlockwise. In their most recent article, they also demonstrate that they can now switch between these preference positions using light. “This is important for controlling whether the read/write head writes a zero or a one,” explains Elemans.
They achieved this by building an extra molecular machine on the read/write head. This can carry out controllable movements under the influence of light, a discovery for which Ben Feringa, professor in organic chemistry at the University of Groningen and co-author of the article, received the Nobel Prize in 2016. This tiny machine can be seen as a paddle wheel that rotates when light falls on it. This then rotates the read/write head, changing its direction from clockwise to anticlockwise or vice versa.
Now that the read/write head can be controlled, the next step is to actually write zeros and ones onto the thread. “We might be able to do it tomorrow, but it could easily take a year as well, unfortunately it’s difficult to predict,” says Elemans.
Photo: Alexas_Fotos via Pixabay.