One of the most promising approaches to artificial intelligence is trying to mimic how the human brain works with software. Scientists have been working on what they hoped would open a new frontier in neuromorphic computing for over a decade now. At the time, making a device using miniature tools that functioned as real brain synapses was almost a fantasy. Although an Australian startup (Cortical Labs ) has gone one step further: It is building miniature brains without a body, using real biological neurons embedded in a specialized microchip.
Melbourne-based Cortical Labs hopes to teach these hybrid mini brains to perform many of the tasks that software-based artificial intelligence formalizes, but at a fraction of the power consumption. The company is currently working to source its mini brains, which so far are approaching the processing power of a dragonfly brain, to play Atari’s arcade video game “Pong.” Pong was one of the first games that DeepMind used to demonstrate its performance as an AI. Precisely this demonstration led to Google launching to buy DeepMind the following year, in 2014.
A chip 100 times smaller than a human hair
The biggest obstacle to neuromorphic computing, making it seem unattainable, is that most common computers run at more than 1 volt to perform their operations. However, the brain sends signals between neurons consuming around 80 millivolts, which is much lower . After decades of experiments, the scientists achieved a memory voltage in a range similar to conventional computers, but to be below that seemed unlikely.
Now a team at the University of Massachusetts has discovered, while trying to better understand protein nanowires, how to use these biological filaments that conduct electricity to create a neuromorphic device, or “memory transistor.” They used protein nanowires developed at UMass Amherst from Geobacter bacteria by microbiologist and co-author Derek Lovely, and conducted experiments in which the device reached neurological voltages.
It works extremely efficiently with very little power, just like human brains do, and is 100 times smaller than the diameter of a human hair. And yes, it is capable of replicating the activity of a biological brain with the same neurological voltage.
“This is the first time that a device can operate at the same voltage level as the brain. No one would have expected that we could create a device that is as energy efficient as the biological counterparts in a brain. Still, we now have real evidence for ultra-low-power computing capabilities . “
Geobacter’s electrically conductive protein nanowires offer many advantages over expensive silicon nanowires, which require toxic chemicals and high-energy processes to be manufactured. In addition, they are more stable in water or body fluids, an important characteristic for biomedical applications.
It is clear that this project is far from being completed, that is, to achieve computers as efficient as the biological brain, but it is a really remarkable step that brings electronics and biology a little closer .
“You can modulate the conductivity or plasticity of the nanowire-memristor synapse so that it can emulate biological components for brain-inspired computing. Compared to a conventional computer, this device has a learning capability that is not software-based. “, explains Tianda Fu, leader of the work published in the journal Nature.
Referencia: Bioinspired bio-voltage memristors, Nature Communications, DOI: 10.1038/s41467-020-15759-y , https://www.nature.com/articles/s41467-020-15759-y
