The human brain is still a far more powerful computer than anything it itself has created so far. It's no wonder then that engineers have recently focused on trying to emulate the structure of the brain with artificial synapses. Now, a team of researchers has made a new artificial synapse design that works using a light-based biotechnology technique called optogenetics.

The field of optogenetics is all about using pulses of light to affect change in the electrical activity of cells. Past research has experimented with the method in order to study neurons in the brain, reset our biological clocks, adjust pain thresholds, and even correct dangerously irregular heartbeats.

The new computer chip, developed by researchers at RMIT, Australian National University, Colorado State University and Queensland University of Technology, was designed to run on optogenetic principles and function like the brain. To do so it uses light of different colors to write, process and erase data.

"Our optogenetically-inspired chip imitates the fundamental biology of nature's best computer – the human brain," says Sumeet Walia, lead researcher on the study. "Being able to store, delete and process information is critical for computing, and the brain does this extremely efficiently. We're able to simulate the brain's neural approach simply by shining different colors onto our chip."

A photocurrent is created on the chip using light, and changing the color changes the direction, or polarity. Doing this over and over, in a certain pattern, allows the artificial synapse to create and break connections between components, similar to how neurons in the brain pass messages along to form memories.

The chip is built with black phosphorus, a semiconducting material that's emerging as a potentially important part of future electronics. Its usefulness can often be diminished by natural defects, but in this case the researchers used them for their benefit.

The researchers say the chip could find use in wearable electronic devices, and helps advance two fields of computing – light-based and brain-inspired devices.

"This technology takes us further on the path towards fast, efficient and secure light-based computing," says Walia. "It also brings us an important step closer to the realization of a bionic brain – a brain-on-a-chip that can learn from its environment just like humans do."

The research was published in the journal Advanced Functional Materials.

Source: RMIT

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