Memristors as synaptic emulators for neuromorphic computing

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The accumulation and extrusion of Ca2+ in the pre- and postsynaptic compartments play a critical role in initiating plastic changes in biological synapses. To emulate this fundamental process in electronic devices, we developed diffusive Ag-in-oxide memristors with a temporal response during and after stimulation similar to that of the synaptic Ca2+ dynamics. In situ high-resolution transmission electron microscopy and nanoparticle dynamics simulations both demonstrate that Ag atoms disperse under electrical bias and regroup spontaneously under zero bias because of interfacial energy minimization, closely resembling synaptic influx and extrusion of Ca2+, respectively. The diffusive memristor and its dynamics enable a direct emulation of both short- and long-term plasticity of biological synapses, representing an advance in hardware implementation of neuromorphic functionalities.

Neuromorphic computing uses structures or systems that are similar to those used in the human brain. Structures such as neurons and synapses.

If scientists and engineers are successful then they would be able to create systems that function like the human brain using comparable scale systems that emulated human neurons and synapses.

Memristors are promising in that there have already been hundreds of millions of memristors produced on single chips and it appears promising that memristors could be scaled to trillions in a few or single chips.

Current studies estimate that the average adult male human brain contains approximately 86 billion neurons. As a single neuron has hundreds to thousands of synapses, the estimated number of these functional contacts is much higher, in the trillions

Highly nonlinear, fast and repeatable threshold switching behaviours of diffusive memristors

Nature Materials- Memristors with diffusive dynamics as synaptic emulators for neuromorphic computing

13 pages of supplemental material

SOURCE – Nature Materials