Scientists in Switzerland have discovered that a compound used in electronics is capable of “remembering” previous external stimuli in a similar way to neurons in the human brain.
Mohammad Samizadeh Nikoo, a PhD student in electrical engineering at Polytechnic University of Lausanne’s POWERlab, made the chance discovery while conducting research on vanadium dioxide (VO2).
For his thesis, he set out to discover how long it takes for VO2 to transition from one state to another. In doing so, he observed a memory effect in the material’s structure.
This is the first material to be identified as possessing this property, but there could be others out there.
The findings, published in the journal Nature, could have major implications for the future of electronic devices, in particular when it comes to data processing and storage.
Behaving like neurons
"Vanadium oxide can show neuron-like activation, meaning it can pass electric current under certain conditions which are very similar to neurons," Samizadeh Nikoo told Euronews Next.
In his experiments, Samizadeh Nikoo applied an electric current to a sample of VO2. The current moved across the material, following a path until it exited on the other side, he explained.
As the current heated up the sample, it caused the VO2 to change state. Once the current had passed, the material returned to its initial state.
Samizadeh Nikoo then applied a second current pulse to the material, and saw that the time it took to change state was directly linked to the history of the material.
"The VO2 seemed to 'remember' the first phase transition and anticipate the next," Professor Elison Matioli, who heads the POWERlab, said in a statement.
"We didn’t expect to see this kind of memory effect, and it has nothing to do with electronic states but rather with the physical structure of the material. It’s a novel discovery: no other material behaves in this way".
A memory of up to three hours
The researchers went on to find that VO2 is capable of remembering its most recent external stimulus for up to three hours.
"The memory effect could in fact persist for several days, but we don’t currently have the instruments needed to measure that," Matioli said.
The researchers say the discovery is important because engineers rely on memory to perform calculations of all kinds, and materials offering greater capacity, speed, and miniaturisation in this process are in high demand. VO2 now appears to tick all three of these boxes.
"We discovered that these activation conditions are completely related to the history and background of vanadium oxide and actually, it is related to its previous activations. This is exactly the same as what happens in our brain," said Samizadeh Nikoo.
"When we recognise someone, a series of neurons are activating, and a memory is forming in our brain. When we meet the same person again, those neurons can be activated much faster and by using less energy".
"So, the behaviour of this electronic component is very similar to neurons,” he said, adding that by connecting these electronic components together, it could be possible to produce the same kinds of neural networks as in our brains – making this compound “a very good candidate for artificial intelligence".