The Artificial Neuron

IBM Creates World’s First Artificial Phase-Change Neurons

They behave like biological neurons, including low power usage and dense scaling.

Sebastian Anthony | August 3, 2016

IBM Research in Zurich has created the world's first artificial nanoscale stochastic phase-change neurons. IBM has already created a population of 500 of these artificial neurons and used them to process a signal in a brain-like (neuromorphic) way.
This breakthrough is particularly notable because the phase-change neurons are fashioned out of well-understood materials that can scale down to a few nanometres, and because they are capable of firing at high speed but with low energy requirements. Also important is the neurons' stochasticity—that is, their ability to always produce slightly different, random results, like biological neurons.
Enough fluff—let's talk about how these phase-change neurons are actually constructed. At this point, it might help if you look at the first diagram in the gallery.

"Phase-change neurons. A chip with large arrays of phase-change devices that store the state of artificial neuronal populations in their atomic configuration. In the photograph, individual devices are accessed by means of an array of probes to allow for precise characterization, modeling and interrogation. The tiny squares are contact pads that are used to access the nanometer-scale phase-change cells (not visible). The sharp probes touch the contact pads to change the phase configuration stored in the cells in response to the neuronal input. Each set of probes can access a population of 100 cells." Source: https://www.flickr.com/photos/ibm_research_zurich/28351591461/in/photostream/

"An artistic rendering of a population of stochastic phase-change neurons which appears on the cover of Nature Nanotechnology, 3 August 2016. IBM scientists have created randomly spiking neurons using phase-change materials to store and process data. This demonstration marks a significant step forward in the development of energy-efficient, ultra-dense integrated neuromorphic technologies for applications in cognitive computing." Source: https://www.flickr.com/photos/ibm_research_zurich/27647743543/in/photostream/

<more at http://arstechnica.com/gadgets/2016/08/ibm-phase-change-neurons/; related articles and links: http://www.economist.com/news/science-and-technology/21703301-narrowing-gap-between-biological-brains-and-electronic-ones-researchers-have (Researchers have built an artificial neuron. 
Narrowing the gap between biological brains and electronic ones. August 3, 2016) and http://www.forbes.com/sites/federicoguerrini/2016/05/22/neuron-based-chips-will-soon-become-commonplace-this-startup-founder-says/#3fb68738bb2f (Neuron-Based Chips Will Soon Become Commonplace, This Startup Founder Says. May 22, 2016)>