A new study shows innovative brain-like computing at molecular levels

Researchers have revealed, for the first time ever, that abrain-like computing system is possible at the smallest scale of atoms.

The study was conducted at the University of Limerick’s (UL)
Bernal Institute in Ireland by a team of researchers from across the globe who created a
new type of organic material that can learn from its prior behavior.

The researchers discovered a dynamic molecular switch that
emulates synaptic behavior, or communication between neurons.

The study was published today, Nov. 21, in the journal Nature Materials.

The research team was led by Damien Thompson, a professor of Molecular
Modelling in UL’s Department of Physics and director of SSPC, the UL-hosted
Science Foundation Ireland Research Centre for Pharmaceuticals, along with
Christian Nijhuis at the Centre for Molecules and Brain-Inspired Nano Systems
in the University of Twente and Enrique del Barco from the University of Central
Florida.

Development

The team created a two-nanometer-thick layer of molecules. The
size, in comparison, is 50,000 times thinner than a strand of hair, and it has
the ability to remember its history as electrons pass through. “Switching
probability and the values of the on/off states continually change in the
molecular material, which provides a disruptive new alternative to conventional
silicon-based digital switches that can only ever be either on or off” said
Thompson.

The research team demonstrated the new materials and properties
of them by using experimental characterizations and electrical measurements. These
dimensions were supported by multi-scale model systems spanning from predictability
of the molecular structures to analytical mathematical modeling of the
electrical information.

Creating the novel material through imitating biological properties

The novel dynamic behavior of the synapses at the molecular
level was imitated by combining fast electron transfer with slower proton
coupling limited by diffusion, similar to the role of biological calcium ions
or neurotransmitters, the study stated.

The behavior also displays all the mathematical logic functions
needed in deep learning, a subset of machine learning within artificial
intelligence. In doing so, it successfully emulated Pavlovian ‘call and
response’ synaptic brain-like behavior. In Pavlovian response, Nobel Prize-winning
physiologist Ivan Pavlov found that dogs, and other animals, could be
conditioned to respond involuntarily to rewards, which became the ideology of
classical conditioning.

The transformation can emulate the plasticity of synapse neuronal
junctions, which are the sites where the transmission of electric nerve
impulses occur between two neurons. “The community has long known that silicon
technology works completely differently from how our brains work and so we used
new types of electronic materials based on soft molecules to emulate brain-like
computing networks,” said Thompson.

Future applications

The team was able to combine their knowledge and skills in “materials
modeling, synthesis, and characterization to the point where we could
demonstrate these new brain-like computing properties,” Thompson stated.

The researchers mentioned that the method and new material
can be applied to dynamic molecular systems driven by other stimuli in the
future, such as light, and added to different kinds of dynamic
covalent bond formation, in which the material would use its plasticity to remember
and take the shape of various other materials.

“This is just the start. We are already busy expanding this
next generation of intelligent molecular materials, which is enabling
development of sustainable alternative technologies to tackle grand challenges
in energy, environment, and health,” said Thompson.

Norelee Kennedy, professor and vice president of research at
UL, agrees. “Our researchers are continuously finding new ways of making more
effective, more sustainable materials,” Kennedy stated. “This latest finding is
very exciting, demonstrating the reach and ambition of our international
collaborations and showcasing our world-leading ability at UL to encode useful
properties into organic materials,” she continued.