London, March 16 (ANI): Reports indicate that a US military-funded project is trying to use the memristor, the "missing link of electronics", to make brain-like computers, which would bring neural computing closer to reality.
It seems the so-called memristor can behave uncannily like the junctions between neurons in the brain.
A memristor is a device that, like a resistor, opposes the passage of current. But memristors also have a memory.
The resistance of a memristor at any moment depends on the last voltage it experienced, so its behaviour can be used to recall past voltages.
Now, memristors are being used in a US military-funded project trying to make brain-like computers, Wei Lu, who led the team at the University of Michigan in Ann Arbor that demonstrated the new behaviour, told New Scientist.
The memristor's existence was predicted in 1971, when Leon Chua of the University of California, Berkeley, spotted a gap in the capabilities of basic electrical components.
But it was not until 2008 that Stanley Williams at Hewlett-Packard Labs in Palo Alto, California, made the first memristor from a speck of titanium dioxide, the pigment in most white paint.
The race to use memristors in computing has been on ever since, with brain-like computers one of the potential applications.
Memristors lend themselves to the task because the way that their resistance gives a glimpse of an earlier voltage is analogous to the way that a synapse's electrical behaviour is dependent on its past activity.
Lu and colleagues have now provided the first demonstration that the analogy stands up.
What's more, their memristors were built with materials already used in the manufacture of computer chips.
Lu's team used a mixture of silicon and silver to join two metal electrodes where they cross.
The junction mimics a particular behaviour of synapses that allows neurons to learn new firing patterns, and is believed to allow memories to be stored.
In the brain, the timing of electrical signals in two neurons affects the ease with which later messages can jump across the synapse between them.
If the pair fire in close succession, the synapse becomes more likely to pass subsequent messages between the two.
"Cells that fire together, wire together," said Lu.
The Michigan device exhibits the same behaviour.
When the gap between signals on the two electrodes was 20 milliseconds, the resistance to current flowing between the two was roughly half that after signals separated by 40 milliseconds.
"The memristor mimics synaptic action," said Lu, adding that the next step will be to build circuits with tens of thousands of memristor synapses. (ANI)