Scientists from the Jawaharlal Nehru Centre for Advanced Scientific Research in Bengaluru, an autonomous institute of the Department of Science and Technology (DST), have fabricated a device that can mimic human brain cognitive actions. According to a government statement, it is more efficient than conventional techniques in emulating artificial intelligence (AI), thus enhancing the computational speed and power consumption efficiency.
The scientists devised a novel approach of fabricating an artificial synaptic network (ASN) resembling the biological neural network via a simple self-forming method (the device structure is formed by itself while heating). AI is a part of our daily lives, from email filters and predictive text to tools that help battle the COVID-19 pandemic. But AI can do much more. It can facilitate self-driving autonomous vehicles and real-time pattern or image recognition, support augmented reality for healthcare, aid drug discovery, and handle big data. These applications can be achieved with the help of a neuromorphic device, which can mimic human brain synapses to create brain-inspired efficient computing abilities.
The human brain comprises nearly a hundred billion neurons. These neurons massively interconnect with each other via axons and dendrites, forming colossal junctions called synapses. This complex bio-neural network is believed to enable superior cognitive abilities. Aiming to develop a synaptic device for neuromorphic applications with a humble fabrication method, the JNCASR team explored a material system mimicking neuronal bodies and axonal network connectivity much like the biological system. To realise such a structure, they found that a self-forming process was easy, scalable, and cost-effective.
In their research, the JNCASR team dewetted silver to form branched islands and nanoparticles with nanogap separations to resemble bio neurons and neurotransmitters. Dewetting is a process of rupture of continuous film into disconnected islands or spherical particles. With such an architecture, several higher-order cognitive activities are emulated. The fabricated ASN consisted of silver agglomerates networks separated by nanogaps filled with isolated nanoparticles. They found that dewetting silver film at a higher temperature resulted in the formation of island structures separated by nanogaps resembling the bio-neural network.
Using programmed electrical signals as a real-world stimulus, this hierarchical structure emulated various learning activities like short-term and long-term memory, potentiation, depression, associative learning, and interest-based learning, etc. Synaptic fatigue due to excessive learning and its self-recovery was also mimicked. Remarkably, all these behaviours were emulated in a single material system without the aid of external CMOS circuits. A prototype has been developed to emulate Pavlov’s dog’s behaviour, which demonstrates the potential of this device towards neuromorphic artificial intelligence. By organising a nanomaterial resembling the biological neural substance, the JNCASR team has moved a step further in accomplishing advanced neuromorphic artificial intelligence.
“Nature has had an incredible amount of time and diversity to engineer ever new forms and functions through evolution. Learning and emulating new processes, technologies, materials, and devices from nature and biology are the important pathways to the significant advances of the future, which will increasingly integrate the worlds of the living with the man-made technologies,” said Professor Ashutosh Sharma, Secretary, DST.