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Memristors,
short for memory resistors, are a newly understood circuit element for
the development of electronics and have inspired experts to seek ways of
mimicking the behaviour of our own brains’ activity inside a computer.
Research, published today, Monday, 16 May, in IOP Publishing’s Nanotechnology,
explains how the researchers have used highly focused x-rays to map out
the nanoscale physical and chemical properties of these electronic
devices.
It
is thought memristors, with the ability to ‘remember’ the total
electronic charge that passes through them, will be of greatest benefit
when they can act like synapses within electronic circuits, mimicking
the complex network of neurons present in the brain, enabling our own
ability to perceive, think and remember.
Mimicking
biological synapses – the junctions between two neurons where
information is transmitted in our brains – could lead to a wide range of
novel applications, including semi-autonomous robots, if complex
networks of neurons can be reproduced in an artificial system.
In
order for the huge potential of memristors to be utilised, researchers
first need to understand the physical processes that occur within the
memristors at a very small scale.
Memristors
have a very simple structure – often just a thin film made of titanium
dioxide between two metal electrodes – and have been extensively studied
in terms of their electrical properties.
For
the first time, researchers have been able to non-destructively study
the physical properties of memristors allowing for a more detailed
insight into the chemistry and structure changes that occur when the
device is operating.
The
researchers were able to study the exact channel where the resistance
switching of memristors occurs by using a combination of techniques.
They
used highly focused x-rays to locate and image the approximately one
hundred nanometer wide channel where the switching of resistance takes
place, which could then be fed into a mathematical model of how the
memristor heats up.
John
Paul Strachan of the nanoElectronics Research Group, Hewlett-Packard
Labs, California, said: “One of the biggest hurdles in using these
devices is understanding how they work: the microscopic picture for how
they undergo such tremendous and reversible change in resistance.
“We
now have a direct picture for the thermal profile that is highly
localized around this channel during electrical operation, and is likely
to play a large role in accelerating the physics driving the memristive
behavior.”
This research appears as part of a special issue on non-volatile memory based on nanostructures.
