Tag Archives: Guangqiang Liu

Synaptic electronics

There’s been a lot about the memristor, being developed at HP Labs, at the University of Michigan, and elsewhere, on this blog and significantly less on other approaches to creating nanodevices with neuromorphic properties by researchers in Japan and in the US. The Dec. 20, 2012 news item on ScienceDaily notes,

Researchers in Japan and the US propose a nanoionic device with a range of neuromorphic and electrical multifunctions that may allow the fabrication of on-demand configurable circuits, analog memories and digital-neural fused networks in one device architecture.

… Now Rui Yang, Kazuya Terabe and colleagues at the National Institute for Materials Science in Japan and the University of California, Los Angeles, in the US have developed two-, three-terminal WO3-x-based nanoionic devices capable of a broad range of neuromorphic and electrical functions.

The originating Dec. 20, 2012 news release from Japan’s International Center for Materials draws a parallel between the device’s properties and neural behaviour,  explains the ‘why’ of the process, and mentions what applications the researchers believe could be developed,

The researchers draw similarities between the device properties — volatile and non-volatile states and the current fading process following positive voltage pulses — with models for neural behaviour —that is, short- and long-term memory and forgetting processes. They explain the behaviour as the result of oxygen ions migrating within the device in response to the voltage sweeps. Accumulation of the oxygen ions at the electrode leads to Schottky-like potential barriers and the resulting changes in resistance and rectifying characteristics. The stable bipolar switching behaviour at the Pt/WO3-x interface is attributed to the formation of the electric conductive filament and oxygen absorbability of the Pt electrode.

As the researchers conclude, “These capabilities open a new avenue for circuits, analog memories, and artificially fused digital neural networks using on-demand programming by input pulse polarity, magnitude, and repetition history.”

For those who wish to delve more deeply, here’s the citation (from the ScienceDaily news item),

Rui Yang, Kazuya Terabe, Guangqiang Liu, Tohru Tsuruoka, Tsuyoshi Hasegawa, James K. Gimzewski, Masakazu Aono. On-Demand Nanodevice with Electrical and Neuromorphic Multifunction Realized by Local Ion Migration. ACS Nano, 2012; 6 (11): 9515 DOI: 10.1021/nn302510e

The news release does not state explicitly why this would be considered an on-demand device. The article is behind a paywall.

There was a recent attempt to mimic brain processing not based in nanoelectronics but on mimicking brain activity by creating virtual neurons. A Canadian team at the University of Waterloo led by Chris Eliasmith made a sensation  with SPAUN (Semantic Pointer Architecture Unified Network) in late Nov. 2012 (mentioned in my Nov. 29, 2012 posting).