Memristors—Circuit to Flip the Hardware Industry?

You know a technology has arrived when it pops up on a brass rat—and a memristor-shaped building appeared on the Class of 2011 brass rat, says Varun Aggarwal '07, founder of Aspiring Minds, an organization that helps Indian job seekers demonstrate their competence through standardized tests. But "memristor" is not exactly a household word, even though early radios incorporated them and the technology may, for example, replace Flash memory.

Aggarwal was so excited about this concept that he teamed up with a friend, Gaurav Gandhi, to form an organization called mLabs and they created a simple memristor that could be used in electrical engineering higher education, as part of the group's mission to "get kids and young students interested in science and technology." The simple device is made of metallic balls, screws, and a vinyl tube.

"Till now people have been talking of building better computer architectures, better circuits, and even emulating the brain using memristors," he says. "Now, they can actually implement these and test their hypotheses. Our research brings memristor in the reach of everyone: scientists, students, and hobbyists. The availability of this component, cheap and easy to build, will encourage many to explore it and build new applications."

So, what is a memristor?

First envisioned in 1971, part of Wikipedia's definition is a memory resistor or memristor, the "oldest known circuit element with its effects predating the resistor, capacitor, and inductor." An HP team first observed it in 2008—and expectations have been heating up ever since. MLab's short video illustrates the concept and explains how to build a one, devised with imperfect metal point contacts.

What are possible uses for memristors?

"One of the most prevalent applications of memristors is design of highly dense memories," says Aggarwal. "They are slated to replace flash memories in due course. Apart from this, they can be used to build highly efficient computer architectures (including cross bar architecture) and research shows that they can be used to emulate the neuron and thus the brain. Since the component was first observed very recently, in 2008, it is a hot field of research with new applications coming out every day."

Memristors are not really new, says Aggarwal. "We find that the simplest implementation of memristor existed 100 years back and was actively used by radio scientists. It was then called the coherer. It got lost with the invention of vaccuum tube. This helps us see the history of science from a new correcting standpoint. Well, history does repeat itself!"