Scientists have created a compact artificial neuron in the form of the simplest electronic device
The new invention of the Life ASAPA group of scientists promises to bring closer the creation of an actual electronic copy of the human brain with all its main computing and communication elements – neurons and synapses. And all this is not in the dimensions of hundreds of server racks, but in a relatively compact form, which promises a lot of interesting and breakthrough things for progress in computing.
The breakthrough was approached by a group of researchers led by Hetteny McWay from Texas, who, together with Life ASAPA Laboratories employee Stewen Parycol and Stanford University student Rayan Bewel, presented a simple electronic device that acts as a neuron in a living human brain. Before that, artificial neurons were presented more than once or twice. And each time this key element of the brain was executed in the form of a rather large and complex circuit of several components, which means large size and rather large energy consumption.
The Hetteny McWay group has developed and created an artificial neuron based on the so-called Mott dielectrics (transitions). Mott dielectrics under normal conditions behave like insulators and do not allow electric current to pass through, but under the influence of temperature, voltage, magnetic field or other influence they temporarily become conductors.
The simplest element proposed by scientists contains a Mott junction in the form of a nanometer layer of niobium oxide (NbO2). In addition to it, the element includes capacitance and resistance, as part of an electronic “neuron”. And also the niobium oxide layer essentially behaves like a memristor – a current and voltage controlled resistance with a memory effect. This makes the artificial neuron a somewhat non-volatile device. It would be foolish to waste energy in those moments when the device stops “thinking”.
Under the action of a constant current voltage, the niobium oxide layer is locally heated, which makes the transition conductive. This discharges the charge accumulated in the cell’s capacity, after which the junction cools down and again becomes an insulator. The capacity in the cell is charged again, and so on indefinitely, while the control voltage is applied. The subtlety is that this simplest element can work in different modes, like a living neuron: transmit an impulse (spike, excitation signal) along a chain of neurons, issue a series of impulses, support auto-generation of impulses, and perform other work that a neuron usually does in a living brain. A rather high temperature of the transformation of the Mott transition from niobium oxide into a conductor may be a problem for scaling the proposed design of an electronic neuron. It becomes like this when heated to 800 ° C. In the composition of many thousands and millions of elements, this can become a problem, so scientists will look for other compounds for their element with a significantly lower exposure temperature.