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Gold Disk Could Store “Long Data” for Centuries

Scientists have drawn on the durable power of gold to demonstrate a new type of high-capacity optical disk that can hold data securely for more than 600 years.

The technology could offer a more cost-efficient and sustainable solution to the global data storage problem while enabling the critical pivot from Big Data to Long Data, opening up new realms of scientific discovery over generations.

The recent explosion of Big Data and cloud storage has led to a parallel explosion in power-hungry data centres. These centres not only use up colossal amounts of energy – consuming about 3% of the world’s electricity supply – but largely rely on hard disk drives that have limited capacity of up to 2 TB per disk and lifespans limited to 2 years.

Now scientists from RMIT University have used gold nanomaterials in an optical disk with up to 10 TB capacity and a lifespan of six centuries.

The novel technique behind the technology combines gold nanomaterials with a hybrid glass material that has outstanding mechanical strength. Glass is a highly durable material that can last up to 1000 years and can be used to hold data, but has limited storage capacity because of its inflexibility. However, the team combined glass with an organic material, halving its lifespan but radically increasing its capacity.

To create the nanoplasmonic hybrid glass matrix, gold nanorods were incorporated into a hybrid glass composite known as an organic modified ceramic. The researchers chose gold because, like glass, it is robust and highly durable. Gold nanoparticles allow information to be recorded in five dimensions – the three dimensions of space plus colour and polarisation.

The technique relies on a sol-gel process that uses chemical precursors to produce ceramics and glasses with better purity and homogeneity than conventional processes.

The technology could radically improve the energy efficiency of data centres – using 1000 times less power than a hard disk centre – by requiring far less cooling and doing away with the energy-intensive task of data migration every 2 years. Optical disks are also inherently far more secure than hard disks.

“All the data we’re generating in the Big Data era – over 2.5 quintillion bytes a day – has to be stored somewhere, but our current storage technologies were developed in different times,” said lead investigator Prof Min Gu of RMIT University’s Laboratory of

Artificial-Intelligence Nanophotonics. “While optical technology can expand capacity, the most advanced optical disks developed so far have only 50-year lifespans. Our technique can create an optical disk with the largest capacity of any optical technology developed to date, and our tests have shown it will last over half a millennium. While there is further work needed to optimise the technology… we know this technique is suitable for mass production of optical disks.”

The world is shifting from Big Data towards Long Data, which enables new insights to be discovered through the mining of massive datasets that capture changes in the real world over decades and centuries.

Lead author of the paper published in Nature Communications (, Dr Qiming Zhang of RMIT, said the new technology could advance the rise of Long Data, which “offers an unprecedented opportunity for new discoveries in almost every field… but we can’t unlock that potential without addressing the storage challenge.

“For example, to study the mutation of just one human family tree, 8 TB of data is required to analyse the genomes across ten generations. In astronomy, the Square Kilometre Array radio telescope produces 576 petabytes of raw data per hour. Meanwhile the Brain Research through Advancing Innovative Neuro­technologies (BRAIN) Initiative to ‘map’ the human brain is handling data measured in yottabytes, or one trillion terabytes.

“These enormous amounts of data have to last over generations to be meaningful. Developing storage devices with both high capacity and long lifespan is essential so we can realise the impact that research using Long Data can make in the world.”

The latest development progresses earlier work by Gu’s team that smashed through the seemingly unbreakable optical limit of blu-ray and enabled data to be stored across the full spectrum of visible light rays.