TECHNOLOGY FOR CHANGE

Brain Synapse Simulated by Transistor

Dave Greenfield | Date: 03-15-10 | Comments

A new transistor that can mimic the complex process of neurons firing messages to each other through synapses is leading electronics one step toward behaving, or at least thinking, like humans.

Researchers led by physicist Dominique Vuillaume of the Institute of Electronics, Microelectronics, and Nanotechnology in France have developed a new transistor that can mimic the complex process of neurons firing messages to each other, as well as to muscles and glands, through synapses�leading electronics one step toward behaving, or at least thinking, like humans.

Every thought, every perception and every movement is made possible by complex computations as neurons fire messages to each other, as well as to muscles and glands. Synapses are the junctions through which these messages travel. There are about a billion synapses in every cubic millimeter of cerebral cortex�an incredible 100 trillion to 500 trillion in an adult brain.

The New Transistor Technology

A biological neuron is converted by a synapse into neurotransmitters, or chemicals, that help facilitate communication between neurons and cells. The nanoparticle organic memory field-effect transistor (NOMFET) uses gold nanoparticles, a layer of insulation and a layer of pentacene, an organic semiconductor. The gold nanoparticles were positioned in a trough between two electrodes and covered with pentacene. Missing electrons in the conductive material created positive charges that transmitted the current across the nanoparticles. There are voltage points, like the brain�s synapses, where some of these charges are temporarily trapped by the nanoparticles. Depending on the voltage Vuillaume and his team used, the outputs were stronger or weaker. This mimics biological short-term plasticity.

NOMFET is the most flexible and efficient transistor to mimic synaptic behavior to date, and could well lead to computers that are able to mimic human thought processes to an extent. Image processing, recognition and more complex tasks would be handled more efficiently by such computers. The technology could also be used to attach artificial devices to living biological tissue. While computers will not be able to re-create human thoughts exactly like a living, breathing person, this advance put science fiction a little closer to fact.