The brain-mimicking chip uses light to create memories

Electronic Chip Imitates A Human Brain To Make Memories

Can a computer chip really mimic a human's brain?
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The human brain is the perfect computer that can store, delete, and process information. The researchers at RMIT University (Australia) have taken motivation from optogenetics, an emerging tool in biotechnology, to make a device that replicates the way the brain stores and loses information. Optogenetics involves the use of light to control cells in living tissue, typically neurons.

This enables scientists to probe into the body’s electrical system with high accuracy, using light to manipulate neurons which can be turned off or on.

How Do The Neurons Work?

Neural connections occur in within the brain via electrical impulses. When small energy spikes reach a specific threshold voltage, the neurons bind together – and you’ve started creating a memory.

Similar Technique to Design Computer Chips?

The new chip is built on an ultra-thin material that changes electrical resistance in reaction to different wavelengths of light, enabling it to replicate the way neurons work to store and delete information in the brain. This, in turn, can simulate the brain’s inner workings by merely shining different colors onto the chip.

Dr. Sumeet Walia, who led the research team, says the technology has many applications in artificial intelligence (AI) technology that can hopefully harness the brain’s full sophisticated functionality.

“Our optogenetically-inspired chip mimics the fundamental biology of nature’s best computer — the human brain,” Dr. Walia said. “Being able to delete, store, and process information is critical for computing, and our brain does this extremely efficiently. We’re able to stimulate the brain’s neural approach merely by shining different colors onto our chip.”

The lead author of the study published in Advanced Functional Materials, Taimur Ahmed, said being able to replicate neural behavior on a computer chip offered many exciting avenues for research across different sectors. “This technology creates tremendous opportunities for researchers and scientists to understand better the human brain and how it is affected by disorders that disrupt neural connections, like and dementia and Alzheimer’s disease,” Ahmed said.

More on, the researchers, from the Functional Materials and Microsystems Research Group at RMIT, have also demonstrated the chip can perform logical operations in which several inputs can be merged to give a desirable output. This adds to another brain-like functionality of the chip. Developed at RMIT’s MicroNano Research Facility, the tech is well-matched with existing electronics and computer chips and has also been demonstrated on a flexible platform. Hence it can also be integrated into wearable electronics.

How the chip works

Shining a light onto the chip produces an electric current in the chip’s light-sensitive material. Switching between the colors causes the current to reverse direction from negative to positive.

This polarity switch is equivalent to the binding and breaking of connections between neurons in our brains, a mechanism that enables neurons to connect and make new memories or disconnect and forget them again.

It is very similar to optogenetics, in which light-induced modification of neurons causes them to turn off or on, inhibiting or enabling connections to the next neuron in the chain. This light-based process is what the chip can now replicate.

The researchers in their attempt to develop the technology used a material called “black phosphorus,” with a slightly deformed molecular structure due to some missing atoms. Defects like these are usually considered a problem for electronics; however, the researchers exploited it to create new functionality. The flaw allows manipulating the material’s behavior to imitate both neural connections and disconnections, depending on the wavelength of light shining on it.

“Defects are commonly looked on as something that should be avoided, but here we are using them to create something beneficial and novel,” told Ahmed. “It is a creative approach to finding solutions for the many technical challenges we face.”

The Future

So how does this new chip help in the future? The new chip will inevitably move towards fast, efficient, and secure light-based computing.

New chip is based on an ultra-thin material that changes electrical resistance

The New chip is based on ultra-thin material that changes resistance with color

It can also move ahead in the direction of creating a bionic brain that can learn from its environment just like we do. It can also open doors for research to understand the brain better and how it is affected by ailments that disrupt neural connections, such as some forms of dementia, including Alzheimer’s disease.

Our brain is made up of billions of neurons in connected networks. They connect with each other by using a sequence of electrical signals to express different behaviors, for example learning through sensory organs or more complicated processes like memory and emotions. A disturbance to these signaling orders can lead to a loss of these vital neural connections, possibly causing memory loss and dementia.

It is important to identify the damaged neurons and reestablishing their signaling route without disturbing the functioning of other neurons in the system to cure the disorder.  With a computer model of the brain, neuroscientists will be able to simulate brain abnormalities and functions and work towards cures, without the need for living test subjects.

Our hopes are still high that this technology could interface with living tissues, leading to the development of bionic devices like retinal implants. The chip responds differently to different wavelengths and can possibly be used to make artificial retinas. The retina in the human eye contains cells that are sensitive to varying wavelengths of light, generating a signal that the brain interprets as different colors.

This technology can also be incorporated into wearable electronics, bionic prosthetics, or smart gadgets imbued with artificial intelligence. However, like any other technology, there are many obstacles before it can be commercialized. There is still a very long way to build a network as big and sophisticated as a human’s brain or even a small segment of it that could be very useful to neuroscientists.

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