Marb's Lab Cooks Up a Memristor Emulator, Ahead of a Planned Peceptron Analog Computer Build

Mononymous self-described "citizen scientist" Marb, of YouTube channel Marb's Lab, is playing around with memristor technology — by building a galvanically-isolated emulator that can be hooked up to an Arduino microcontroller for experimentation.

"The reason why I am interested in memristors is mainly to build an analog computer based on analog perceptrons," Marb explains. "A perceptron is a highly simplified model of a biological neuron. Although memristors are already available to buy […] they are still quite expensive and very sensitive. Measuring the resistance of the memristor with a standard multimeter would destroy it. I have therefore decided to build a memristor emulator for initial experiments."

A portmanteau of "memory" and "resistor," the "memristor" was first proposed as a fundamental electrical component in 1971 by Leon Chua — sitting alongside the more common resistor, capacitor, and inductor as the fourth in the family. Their applicability to perceptrons is simple: Frank Rosenblatt's Mark I analog computer, which built on the concept of perceptrons, used motorized potentiometers that Marb describes as acting like "a kind of mechanical memristor."

Off-the-shelf memristors are, as Marb notes, rather too sensitive for the sort of project the maker has planned, which is where the emulator comes in. Built on a single PCB — and galvanically isolated, as in Rosenblatt's potentiometer design — Marb's creation is designed to act exactly like an ideal memristor, operating bidirectionally across its two connections.

When voltage is applied across the emulator memristor's input, its resistance value changes — and that change is retained even after power-off, giving the component its vital "memory" aspect. This will be key to Marb's planned perceptron computer — though that'll take quite a few more memristors yet.

The project is documented in the video embedded above and on the Marb's Lab YouTube channel.