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 ")

Google Now Expects Chips To Design Themselves
'What lay down there? Energy, tubes and pipes, wiring, transformers, self-contained machinery...' - Philip K. Dick, 1960.

Neuromorphic Computing Hardare
'He had constructed an organ, a brain, of metal, entirely inorganic and lifeless...' - Edmond Hamilton, 1926.

Finally! Microsoft Surface Neo And Surface Duo Implement Excellent Courier Idea
'Runcible, whose pages were thicker and more densely packed with computational machinery...' - Neal Stephenson, 1995.

Tap Strap 2 Now With Air Mouse
'He waved his hand and the circuit switched abruptly.' - Philip K. Dick, 1955.

 

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

Cute Teddy Bear Robot Favorite Of Hospitalized Children
'...thought had been given to its programming.'

Google Now Expects Chips To Design Themselves
'What lay down there? Energy, tubes and pipes, wiring, transformers, self-contained machinery...'

PRAM Solar Powered Satellite Hardware Tested In Orbit
'Our beams feed these worlds energy drawn from... the Sun'

3D Printed Glass Uses Stereolithography Techniques
'All that with glass...'

Science Fiction Helps Young Readers Build Resiliency
'Reading science fiction and fantasy can help readers make sense of the world.'

I Want My 1928 Telestereo Hologram Now
'Instantly there appeared standing upon the disk, the image of a man...'

Memes Now Come From Neural Nets
'Your order said for him to be able to be able to work out twists on the gags in the file...'

Robot Dog Learns To Be Doggy From Real Dogs
'So we took pictures of Guzub making a Three Planets, and I could construct this one to do it exactly right down to the thousandth of a second.'

Unwanted Cruise Ships Huddle Together Out At Sea
'On the screen they passed in an endless, boundaryless flood of green specks...'

Sono Sion Electric Car Charges As You Drive
'It drew its power from six square yards of sunpower screens on its low curved roof.'

News Mood Filter Web Extension
'He adjusted the n, the r and b knobs, and hopefully anticipated a turn for the better...'

Fetal Lamb Rests In Artificial Womb
'... stewing warm on their cushion of peritoneum and gorged with blood-surrogate and hormones, the foetuses grew and grew...'

MIT Wants To Catch Interstellar Visitors
'INVESTIGATE MYSTERIOUS OBJECT ENTERING NEW CALEDONIA SYSTEM FROM NORMAL SPACE'

AutoX Sets Up Asia's Largest Robotaxi Center
'The robot cab seemed to know where it was going and, no doubt, the master machine from which it received its signals knew.'

E - Ink's Automatic Self Styling Color-Changing Dress
'The racks of gowns itched and quivered, their colors running into blurred pools.'

Soft Robots Use Kirigami Piezoelectric Sensor Skin
'A worthy opponent was the golem.'

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.