Scientists from RMIT University in Australia and the Wuhan
Institute of Technology in China have used
gold nanomaterials to demonstrate an optical disk with up to 10TB capacity and
a six-century lifespan. This represents a storage improvement of 400 per cent
over current technologies.
The researchers demonstrated optical long data memory in a
novel nanoplasmonic hybrid glass matrix, different to the conventional
materials used in optical discs.
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. The team combined glass with an organic material, resulting
in half the lifespan but significantly increased capacity.
Gold nanorods were incorporated into a hybrid glass
composite, known as organic modified ceramic, to create the nanoplasmonic
hybrid glass matrix.
Gold was selected because it is robust and highly durable,
like glass. Gold nanoparticles allow information to be recorded in five
dimensions – the three dimensions in space plus colour and polarisation.
The technique relies on a sol-gel
process, which uses chemical precursors to produce ceramics and glasses with
better purity and homogeneity as compared to conventional processes.
Benefits of the
technology
The explosion of Big Data and cloud storage in recent years
has led to a parallel rise in the requirement for power-hungry data centres. Dtheata
centres consume about 3 per cent of the world’s electricity supply and largely
rely on hard disk drives that have limited capacity of up to 2TB per disk and
lifespans of up to two years.
This new technology could lead to a radical improvement in
the energy efficiency of data centres – using 1000 times less power than a hard
disk centre – by requiring significantly less cooling and eliminating the
energy-intensive task of data migration every two years. Optical disks are also
inherently more secure than hard disks.
Though the researchers know that the technique is suitable
for mass production of optical disks, further work is required to optimise the
technology and they are keen to partner with industrial collaborators to drive
the research forward.
The jump in capacity and lifespan would also enable a shift
from big data to long data, enabling the discovery of new insights through the
mining and preservation of huge datasets that capture changes in the real world
over decades and centuries (In a longitudinal study, data is gathered for the
same subjects repeatedly over a period of time).
Lead author, Senior Research Fellow Dr Qiming Zhang from
RMIT’s School
of Science, talked about the opportunities afforded by long data which cannot
be unlocked without addressing the storage challenge.
“For example, to study the mutation of just one human family
tree, 8 terabytes of data is required to analyse the genomes across 10
generations. In astronomy, the Square Kilometre Array (SKA) 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,” he added.
Lead investigator, RMIT's Distinguished Professor Min Gu,
said, “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. 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.”
The research builds on previous work by Gu and his team that
surpassed the seemingly unbreakable optical limit of blu-ray and enabled data
to be stored across the full spectrum of visible light rays.
The research was led by Gu and Zhang at RMIT’s Laboratory
of Artificial-Intelligence Nanophotonics and the RMIT node of Centre
for Ultrahigh bandwidth Devices for Optical Systems (CUDOS), together with
collaborators from the School of Materials Science and Engineering at Wuhan
University of Technology and the Faculty of Engineering, Monash University.
The paper, “High-capacity optical long data memory based on
enhanced Young’s modulus in nanoplasmonic hybrid glass composites” is published
in Nature Communications (DOI 10.1038/s41467-018-03589-y).
