Nanoscale device that could spawn a futuristic brain simulator

Even as researchers all across the world are busy developing the idea of brain-inspired computing which is aimed at extending the capabilities of information technology beyond the 'digital logic' or the idea that a two-valued number system can possibly be the basis for the most powerful computers, a new nanoscale electronic synapse developed by a team of researchers at the Stanford School of Engineering promises to herald a new era of computing.

Nanoscale device

The idea

The new device works like the human synapses, or simply tries to emulate the computing mechanism of the human brain. According to the researchers, it has the potential to enable engineers to design small energy-efficient and interactive computer systems that, unlike the present day computers, can learn instead of merely responding to pre-defined programs. The new device will also help in the study of brain by letting the scientists design nanoelectronic versions of different parts of brain.

Brainchild

The Stanford team was led by Professor H.-S. Philip Wong. Duygu Kuzum, Rakesh Jeyasingh and Byoungil Lee were the other members of the team. They are the first group of researchers working in the field of ‘brain-inspired computing’ to have actually developed a commercially viable, small and energy efficient synaptic device. The report was published recently in the online edition of the journal Nano Letters.

The making

At present, computer systems uses 'digital logic' to covey information through the billions of electrical transistors that lie within the nano-scale circuits of computer chips. The speed of the computer depends on the speed and the numbers of transistors packed on a small computer chip.

However, the electronic transistors are nowhere near the synapses that form the basic computational unit of human brain. The junction between two neurons in the nervous system is called as synapse. It enables the transmission of electric messages from one neuron to another and the adaptation of the messages depending on the nature of the incoming signals.

In other words, the synapses, in contrast to the electronic transistors, adapt to changes as they learn. This property is also called as synaptic plasticity. Moreover, they convey more information and consume less energy as compared to the transistors. These analogies have been used by the Stanford team for developing the new device.

What’s new?

The new device artificially emulates synaptic plasticity with the help of a 'phase-change material' technology that is also used for storing information in optical devices like DVDs and CD-ROMs and other memory applications. An alloy of germanium, antimony and tellurium or GST has been used to build the artificials synapses.

What’s refreshing?

According to an estimate, human brain consumes about 10 watts for a basic computation. But for the same task, a super computer can consume upto two to three mega watts of energy. The new device takes us a step closer towards brain like computers which can learn and adapt without any external programming and by consuming less energy.

Application

The new device will also allow the machines of the future to respond faster while performing complex tasks such as face reading and speech recognition. It will immensely help in neuroscience by allowing real-time brain simulations. It will also help in understanding the physics of gradual control of phase-change materials, allowing for additional fine tuning of the synaptic devices and even greater processing ability.