Thursday 1 May 2008

Scientists create missing circuit element "memristor"


23:07' 01/05/2008 (GMT+7)

American electronics experts have finally succeeded in proving the existence of a fourth fundamental unit of electronic circuits: the "memristor," short for "memory resistor."

Researchers in California succeeded in creating a real, working example of the memristor 37 years after its existence was first suggested in 1971, according to the May 1 issue of Nature available on Wednesday.

The memristor was created by Stan Williams of HP Labs in Palo Alto, California, and his colleagues while experimenting with very tiny circuits, who sandwiched a nanoscopic film of a semiconductor(titanium dioxide) between two slivers of metal (platinum). Those are standard materials, the trick is to make the component just 5 nanometers wide, about 10,000 times thinner than a human hair.

It's only at the nanoscale that the behavior of memristors begins to be detectable, said Williams who reported the memristor's creation in Nature.

That's probably one reason why the idea has mouldered on the shelf for 37 years, said Leon Chua, the electrical engineer at the University of California, Berkeley, who first postulated the existence of memristors in a 1971 paper, the report said.

Pleased that his theory has finally been proved, Chua was quoted as saying "I was very excited -- I never thought I would live to see this happen."

Williams explained: "A memristor is essentially a resistor with memory. The actual resistance of the memristor changes depending on the amount of voltage and the time for which that voltage has been applied to the device."

The memristors behave just like ordinary resistors, where resistance is equal to the voltage divided by the current.

That means that a computer created from memristive circuits can "remember" what has happened to it previously, and freeze that memory when the circuit is turned off. This quality could allow computers to turn off and on again in an instant, as all the components could revert to their last state instantly, rather than having to "boot up," he said.

The researchers hope that the new components could revolutionize computing, promising an end to frustrating waits for your computer to boot up.

Most computers use "volatile memory" to perform their running functions, because this offers faster access to data than the non-volatile memory used to store data on hard disks and flash devices such as iPods.

Building computers with memristors might allow a full switch to non-volatile memory, doing away with power-sapping "running memory" and allowing devices to consume far less power when operating.

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