Optogenetics, an emerging tool in biotechnology, was the source of inspiration for RMIT scientists to build a device that simulates the way the brain stores and loses information. Optogenetics allows researchers to probe into the electrical system of the body with extraordinary precision, using light to control neurons so that they can be switched on or off.
The newly developed chip is based on an ultra-thin material that alters electrical resistance in reaction to varying wavelengths of light, allowing it to imitate the way that neurons function to store and erase information in the brain.
Dr Sumeet Walia, research team leader stated the technology paves the way towards artificial intelligence (AI) that can derive the brain’s total advanced functionality.
Our optogenetically-inspired chip imitates the fundamental biology of nature’s best computer— the human brain. 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 colours onto our chip.
Dr Sumeet Walia, Research Team Leader, Functional Materials and Microsystems Research Group, RMIT
Walia continued, “This technology takes us further on the path towards fast, efficient and secure light-based computing. It also brings us an important step closer to the realisation of a bionic brain - a brain-on-a-chip that can learn from its environment just like humans do.”
Dr Taimur Ahmed, study’s lead author said being able to simulate neural behavior on an artificial chip provided stimulating avenues for research spanning various sectors. The research details can be found in Advanced Functional Materials.
“This technology creates tremendous opportunities for researchers to better understand the brain and how it’s affected by disorders that disrupt neural connections, like Alzheimer’s disease and dementia,” Ahmed said.
The scientists, from the Functional Materials and Microsystems Research Group at RMIT, have also shown that the chip can carry out logic operations—information processing—making it another plus point for brain-like functionality.
Built at the Micro Nano Research Facility, the technology is well-matched with current electronics and has also been proven on a flexible platform, for incorporation into wearable electronics.
How the chip works
Neural connections take place in the brain via electrical impulses. When minute energy spikes reach a specific threshold of voltage, the neurons bind together, thereby causing a memory to be created.
In the case of the chip, light is used to produce a photocurrent. Switching between colors makes the current to switch direction from positive to negative.
This direction change, or polarity shift, is equal to the binding and breaking of neural connections, a mechanism that allows neurons to connect (and trigger learning) or hinder (and trigger forgetting).
This is similar to optogenetics, where light-triggered alteration of neurons makes them switch on or off, allowing or hindering connections to the next neuron in the sequence.
To create the technology, the researchers used a material known as black phosphorus (BP) that can be innately imperfect in nature.
This is typically an issue for optoelectronics, but with precision engineering, the scientists were able to make use of the defects to develop new functionality.
Defects are usually looked on as something to be avoided, but here we’re using them to create something novel and useful. It’s a creative approach to finding solutions for the technical challenges we face.
Dr Taimur Ahmed, Study’s Lead Author, RMIT