First Transistor That Mimics Brain Synapse

French researchers have created what they claim is the first transistor to mimic the connections in the human brain. It could lead to neurology-inspired computers, as well as provide a means for connecting artificial devices to existing biological tissue.


(Transistor diagram
Schematic diagram illustrating how the NOMFET (bottom)
mimics a synapse (top). In a synapse, voltage spikes
(blue triangles) are converted to a chemical signal (orange arrow),
which flows across a gap. Once across, the chemical stimulates
the creation of new voltage spikes.
(Courtesy: Dominique Vuillaume))

The team, which includes scientists from the CNRS (the French National Science Agency) and CEA (the French Atomic Energy Commission), began by adding gold nanoparticles to the interface between an insulating layer (gate dielectric) and an organic transistor made of pentacene. They fixed the nanoparticles, which were 5, 10 and 20 nm in diameter, into the source-drain channel of the device using surface chemistry techniques and finished the structure by covering it with a 35 nm thick film of pentacene. The resulting device is called a nanoparticle organic memory field-effect transistor or "NOMFET".

A biological synapse transforms a voltage spike (action potential) arriving from a pre-synaptic neuron into a discharge of chemical neurotransmitters that are then detected by a post-synaptic neuron. These are subsequently transformed into new spikes, leading to a succession of pulses that either become larger or diminish in size. This fundamental property of synaptic behaviour is known as short-term plasticity, which is related to a neural network's ability to learn. It is this plasticity that Vuillaume and colleagues have succeeded in mimicking.

In the NOMFET, the pre-synaptic signal is simply the pulse voltage applied to the device and the output signal is the drain current, explains Vuillaume. The holes – the charge carriers in the p-type organic semiconductor employed – are trapped in the nanoparticles and act like the neurotransmitters. A certain number of holes are trapped for each incoming spike voltage and in the absence of pulses, the holes escape in a matter of seconds

This time delay is carefully adjusted by the researchers by optimizing nanoparticle number and device geometry. "The output of the NOMFET is thus able to reproduce the deceasing or amplifying behaviour typical of a synapse depending on the frequency of spikes," said Vuillaume.

Science fiction fans recall that Isaac Asimov, in his short story Reason, wrote about a similar idea:

All that had been done in the mid 20th century on "calculating machines" had been upset by Robertson and his positronic brain paths. The miles of relays and photocells had given way to the spongy globe of platinum iridium about the size of the human brain. (Read more about the positronic brain)

A few years later, Philip K. Dick had fun with the idea of a Nexus-6 brain unit in his 1968 novel Do Androids Dream of Electric Sheep:

The Nexus-6 did have two trillion constituents plus a choice within a range of ten million possible combinations of cerebral activity. In .45 of a second an android equipped with such a brain could assume any one of fourteen basic reaction-postures. Well, no intelligence test could trap such an andy. But then, intelligence tests hadn't trapped an andy in years, not since the primordial, crude varieties of the 1970's.

From Physics World via Next Big Future.

Scroll down for more stories in the same category. (Story submitted 2/1/2010)

Follow this kind of news @Technovelgy.

| Email | RSS | Blog It | Stumble | del.icio.us | Digg | Reddit |

Would you like to contribute a story tip? It's easy:
Get the URL of the story, and the related sf author, and add it here.

Comment/Join discussion ( 1 )

Related News Stories - (" Computer ")

String Art Courtesy Of Robot Artist
The number of different ways to span a thread between a larger number of hooks is astronomical.

Tetraplegics Dominate Avatar Races
Well, just speaking brain-to-computer...

IBM's Grain Of Sand Computer
'Our ancestors... thought to make the very sand beneath their feet intelligent...' - Stanislaw Lem, 1965.

Can An Entire Brain Be Simulated In A Computer?
'The miles of relays and photocells had given way to the spongy globe of platinum iridium about the size of the human brain.' - Isaac Asimov, 1941.

 

Google
  Web TechNovelgy.com   

Technovelgy (that's tech-novel-gee!) is devoted to the creative science inventions and ideas of sf authors. Look for the Invention Category that interests you, the Glossary, the Invention Timeline, or see what's New.

 

 

 

 

 

Current News

Michelin Self-Sealing Tires On Ford's Explorer
'...a seal of compressed plastifoam to save the air.'

Mushroom Eats Plastic, Saves Planet
Fungus Amongus, SaveUs!

Juggalo Face Paint Disrupts Facial Recognition
'... designed to foil facial recognition systems.'

Mojipic Smart Voice Vehicle Emojis
KITT, what's your response?

Unusual Twist On Woman Dates Robot
'My hearing, vision and awareness went along with that excellent imitation of a young Adonis...'

BrainNet Triple Telepathic Gaming Threat
'In the gloomy half-darkness the three idiots sat babbling.'

AVAS Noisemakers Required For EVs By EU
'...a sound tape to supply the noise of a soi-disant "[internal combustion]" engine...'

Pun Generation Via Neural Nets
'You said you wanted him to be able to distinguish between laugh-power in different gags...'

Blood Battery Robotic Fish
'With one fluid motion, it surged forward, plunged, and was gone.'

Lightyear One Solar-Powered Electric Car (Design By Heinlein)
'It drew its power from six square yards of sunpower screens on its low curved roof.'

'Agression Detectors' Don't Work When Spying On Students
'The professional agitators had also learned how to modulate their voices below the danger level...'

Mining Of Golden Asteroid Foretold In 1898 Science Fiction
'This must be a golden planet—this little asteroid.'

Miners! NASA Wants To License RASSOR Excavator
'The borers had been dismantled and packed away.'

Bee+ Robobee Now With Four Wings
'It was a tiny thing, scarcely more than an inch and a half in length...'

CNSILK Robotic Spider Builder
'We could certainly spin a web right through the Solar System, if we can think of a good use for one.'

Starshade Will Help Space Telescope To Search For Exoplanets
'When it found planetary systems in its field, automatically shifted upon them a higher powered telespectroscope ...'

More SF in the News Stories

More Beyond Technovelgy science news stories

Home | Glossary | Invention Timeline | Category | New | Contact Us | FAQ | Advertise |
Technovelgy.com - where science meets fiction™

Copyright© Technovelgy LLC; all rights reserved.