Peering into the Secret Word of Memristors

We’ve covered the wonder that is Memristors before on iState.  Now comes news that scientists can see how these wonders work from the inside.

Memristors inner workers revealed
Image result for Memristor
Illustration shows an electron beam impinging on a section of a memristor, a device whose resistance depends on the memory of past current flow. As the beam strikes different parts of the memristor, it induces different currents, yielding a complete image of variations in the current throughout the device. Some of these variations in current indicate places where defects may occur, indicated by overlapping circles in the filament (titanium dioxide), where memory is stored. Credit: NIST

Scientists at the National Institute of Standards and Technology (NIST) have now unveiled the long-mysterious inner workings of these semiconductor elements, which can act like the short-term memory of nerve cells.

Just as the ability of one nerve cell to signal another depends on how often the cells have communicated in the recent past, the resistance of a memristor depends on the amount of current that recently flowed through it. Moreover, a memristor retains that memory even when electrical power is switched off.

But despite the keen interest in memristors, scientists have lacked a detailed understanding of how these devices work and have yet to develop a standard toolset to study them.

Now, NIST scientists have identified such a toolset and used it to more deeply probe how memristors operate. Their findings could lead to more efficient operation of the devices and suggest ways to minimize the leakage of current.

Nature Communications – Stateful characterization of resistive switching TiO2 with electron beam induced currents

To explore the electrical function of memristors, the team aimed a tightly focused beam of electrons at different locations on a titanium dioxide memristor. The beam knocked free some of the device’s electrons, which formed ultrasharp images of those locations. The beam also induced four distinct currents to flow within the device. The team determined that the currents are associated with the multiple interfaces between materials in the memristor, which consists of two metal (conducting) layers separated by an insulator.

“We know exactly where each of the currents are coming from because we are controlling the location of the beam that is inducing those currents,” said Hoskins.

Read More at Next Big Future
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Paul Gordon is the publisher and editor of iState.TV. He has published and edited newspapers, poetry magazines and online weekly magazines. He is the director of Social Cognito, an SEO/Web Marketing Company. You can reach Paul at pg@istate.tv