Researcher Jeroen de Vries from the University of Twente Mesa+ institute for nanotechnology has demonstrates that it is possible to store data for extremely long periods. The scientist has created an optical information carrier that can store information for extremely long periods of time, with each bit being written using etching techniques.
Mankind has been storing information for thousands of years. From carvings on marble to today's magnetic data storage. Although the amount of data that can be stored has increased immensely during the past few decades, it is still difficult to actually store data for a long period. The key to successful information storage is to ensure that the information does not get lost. If we want to store information that will exist longer than mankind itself, then different requirements apply than those for a medium for daily information storage. It is possible to conceive of a number of scenarios why we wish to store information for a long time.
"One scenario is that a disaster has devastated the earth and society must rebuild the world. Another scenario could be that we create a kind of legacy for future intelligent life that evolves on Earth or comes from other worlds. You must then think about archival storage of between one million and one billion years," said Jeroen De Vries.
Mr. De Vries has developed an optical information carrier that can store information for extremely long periods of time, with each bit being written using etching techniques. The chosen information carrier is a wafer consisting of tungsten encapsulated by silicon nitride. Tungsten was chosen because it can withstand extreme temperatures. A QR code is etched into the tungsten (see picture) and is protected by the nitride. Each pixel of the large QR code contains a smaller QR code that in turn stores different information.
"In principle, we can store everything on the disc that we believe is worthwhile saving: for example, a digital image of the Mona Lisa. In this study we tested a digital copy of the chapter about this medium from my thesis,” said Mr. De Vries.
In order to ensure the stability of the data, an energy barrier that separates the information from the non-information is required. In order to prove that the data is still legible after millions of years, an ageing test is required to see if the energy barriers are high enough to prevent data loss.
“According to the Arrhenius model, the medium should keep working for at least 1 million years if it is heated to a temperature of 473°K (200°C) and kept in the oven for an hour," noted the scientist.
After the test there was no visible degradation of the tungsten, and it was still easy to read the information. Things become complicated at higher temperatures. When heated to 713°K (440°C) it becomes a lot more difficult to decypher the QR codes even if the tungsten is not affected.
"A follow-up study would be to investigate whether the data carrier also can withstand higher temperatures, for example during a house fire. But if we can find a place that is very stable, such as a nuclear storage facility, then the disc itself and the data that is on it should be able to endure millions of years,” claimed Mr. De Vries.