Deep Geek: Understanding Memristors
December 7, 2008 7:54 PM Subscribe
The coming memristor revolution in electronics and how it works.
posted by NortonDC (43 comments total)
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The newly created memristor, only the fourth fundamental fundamental type of passive circuit element, has the promise of computing advances both prosaic (faster, cheaper and "bigger" flash drives) and momentous (relatively effortless mimicry of brain cells and their activity). This is the story of the memristor's genesis, told by R. Stanley Williams, the leader of the team that created the device.
Being deeply geeky myself, I've read about memristors before, but reading this article and sidebar
finally let me understand how the memristor works and what happens inside it. And that felt pretty damn good.
The article is fantastic, but it does leave one key connection unmade. To create a practical memristor, the team "needed [a] mechanism by which we could change the effective spacing between two wires in our crossbar by 0.3 nm. If we could do that, we would have the 1000:1 [variation in conductivity] we needed... Where would we find a material that could change its physical dimensions like that?" They did create a way to vary that spacing, in a controllable, repeatable, and extremely fast-acting manner, but Williams doesn't directly explain how the internal actions of the switching layer meet that requirement. The payoff for that setup is missing.
When electrical current pushes the conductive impurities in the layer of titanium dioxide toward the other wire, the conductive portion of the layer grows toward the other wire, and the insulating portion of the layer thins.
That thinning is described, but the article never tells the reader that expansion of the conductive layer is that long-sought means of moving the wires.
If you read the article and made that connection before I described it, then you might have felt as smug about it as I did. Williams gets to feel more smug.