"Protonic" artificial synapse runs a million times faster than human ones
Engineers at MIT have developed a new type of artificial synapse that’s extremely energy efficient and ultra-fast, processing data a million times faster than synapses in the human brain. The key is an analog design that shuttles protons around instead of electrons.
The human brain is the most powerful processor in the world, thanks to its unique structure of neurons and synapses. Mimicking this analog setup could make for more powerful computers, which save time and energy by performing operations in tandem and processing data in memory, rather than transferring it between different components. Neural networks make use of this principle, but they have their own hardware limitations.
Now, the MIT team may have cracked one of those limitations. The researchers developed a new type of programmable resistor, which are the building blocks of analog processors. The conductivity of these devices can be switched to conduct or block ions as needed, and an array of these resistors allows information to be processed and transmitted like natural neurons and synapses.
In this case, the team made a few improvements to the formula. First, the resistors are conducting protons, the smallest ions, which can move at blistering speeds with a little help. But the main change is the solid electrolyte, which was made out of phosphosilicate glass (PSG) – essentially, silicon dioxide with a little phosphorus added. This inorganic material was found to have high proton conductivity at room temperature, thanks to its nanoscale pores that allow protons to pass through while blocking electrons.
When a strong electric field of up to 10 volts is applied, the protons zip through the device stack at lightning speeds. That makes for an analog processor that can transmit data a million times faster than previous versions – including the human brain’s synapses.
Importantly, even with all that energy running through it, the resistor doesn’t break down over millions of cycles, because the smaller size and mass of protons means they don’t damage the material. And because PSG is an insulator against electrons, very little electric current runs through the device, keeping it cool and reducing energy usage.
The researchers plan to tweak the design to be able to manufacture these resistors in larger amounts, in order to produce arrays of them to see how they work together. This could ultimately lead to much faster types of computers.
The research was published in the journal Science.