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'Missing link' memristor created: Rewrite the textbooks?

R Colin Johnson

4/30/2008 1:00 PM EDT

PORTLAND, Ore. — The long-sought after memristor--the "missing link" in electronic circuit theory--has been invented by Hewlett Packard Senior Fellow R. Stanley Williams at HP Labs (Palo Alto, Calif.) Memristors--the fourth passive component type after resistors, capacitors and inductors--were postulated in a seminal 1971 paper in the IEEE Transactions on Circuit Theory by professor Leon Chua at the University of California (Berkeley), but their first realization was just announced today by HP. According to Williams and Chua, now virtually every electronics textbook will have to be revised to include the memristor and the new paradigm it represents for electronic circuit theory.

"My situation was similar to that of the Russian chemist Dmitri Mendeleev who invented the periodic table in 1869," said Chua. "Mendeleev postulated that there were elements missing from the table, and now all those elements have been found. Likewise, Stanley Williams at HP Labs has now found the first example of the missing memristor circuit element."

When Chua wrote his seminal paper, he used mathematics to deduce the existence of a fourth circuit element type after resistors, capacitors and inductors, which he called a memristor, because it "remembers" changes in the current passing through it by changing its resistance. Now HP claims to have discovered the first instance of a memristor, which it created with a bi-level titanium dioxide thin-film that changes its resistance when current passes through it.

"This new circuit element solves many problems with circuitry today--since it improves in performance as you scale it down to smaller and smaller sizes," said Chua. "Memristors will enable very small nanoscale devices to be made without generating all the excess heat that scaling down transistors is causing today."

HP has already tested the material in its ultra-high-density crossbar switches, which use nanowires to pack a record 100 Gbits onto a single die--compared with 16 Gbits for the highest density flash memory chips extant.

"We have been looking for years for the best material to use in our ultra-dense nanowire crossbar switches, which can fit 100 billion crossbars into a square centimeter. What we have finally realized is that the ideal material is a memristor," said Williams, primary inventor of the memristor's titanium-dioxide-based material and founding director of HP's 12-year-old Information and Quantum Systems Lab, where his team perfected its formulation.

The hold-up over the last 37 years, according to professor Chua, has been a misconception that has pervaded electronic circuit theory. That misconception is that the fundamental relationship in passive circuitry is between voltage and charge. What the researchers contend is that the fundamental relationship is actually between changes-in-voltage, or flux, and charge. Such is the insight that enabled HP to invent the memristor, according to Chua and Williams.

"Electronic theorists have been using the wrong pair of variables all these years--voltage and charge. The missing part of electronic theory was that the fundamental pair of variables is flux and charge," said Chua. "The situation is analogous to what is called "Aristotle's Law of Motion, which was wrong, because he said that force must be proportional to velocity. That misled people for 2000 years until Newton came along and pointed out that Aristotle was using the wrong variables. Newton said that force is proportional to acceleration--the change in velocity. This is exactly the situation with electronic circuit theory today. All electronic textbooks have been teaching using the wrong variables--voltage and charge--explaining away inaccuracies as anomalies. What they should have been teaching is the relationship between changes in voltage, or flux, and charge."





TimN

4/30/2008 4:42 PM EDT

Very interesting - too late the save the planet though, with all that "now proven" unecessary leakage current out there.
Now we just need the evolutionists to admit their theories are wrong too, hopefully that will be 30 rather than 2000 years

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SPLatMan

4/30/2008 6:29 PM EDT

Neural networks with memristors? Hmmmm, maybe Asimov's positronic brain will have to be renamed memistronic brain :-)

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Phononscattering

5/1/2008 3:32 AM EDT

Why does this article consist of three page of pseudoscientific drivel of it could have a diagram actually showing what the device does? Is this EEtimes or Foxnews?

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kevin_hingwan_yu

5/2/2008 9:49 AM EDT

What is the dimension of memristance compared to ohm=E/ampere, farad=Q/volt and henry=Wb/ampere?

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jeff Rose

5/5/2008 4:24 PM EDT

A quick google of "memistor" shows JPL developed one in 1990. Why didn't the author mention it?

Title: Solid-state thin-film memistor for electronic neural networks

Abstract: This paper reports on a tungsten-oxide-based, nonvolatile, electrically reprogrammable, variable resistance device as an analog synaptic memory connection for electronic neural networks. A voltage controlled, reversible injection of H(+) ions in electrochromic thin films of WO3 is utilized to modulate its resistance. A hygroscopic thin film of Cr2O3 is the source of H(+) ions. The resistance of the device can be tailored and stabilized over a wide dynamic range (about 4 orders of magnitude), and the programming speed is modulated by the control voltage. The suitability of such a device in terms of its response speed, reversibility, stability, and cyclability for its use in electronic neural networks is discussed.

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Da Wiz

5/8/2008 12:55 PM EDT

The fourth component! Neat!
But if resistors are R,
capacitors are -1/omega C,
and inductors are +1/omega L,
where do memristors fit in Z = R+jX?

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HFPack

6/5/2008 11:31 AM EDT

I was wondering about human consciousness in machines after reading about the memristor. I remember something about a Nobel Prize in the mid 1970's which predicted that once a certain threshold of synapic activity happens, that consciousness is obtained. I have also been reading about a new breakthough in electronics (fourth element in integrated circuits) called memristor. It is suppose to memic the synapsic connections in the brain.

Putting these two items together makes me wonder if it is possible to develop consciousness using memristor technology. I read that memristor technology could one day lead to computer systems that can remember and associate patterns in a way similar to how people do. This could be used to substantially improve facial recognition technology or to provide more complex biometric recognition systems that could more effectively restrict access to personal information. These same pattern-matching capabilities could enable appliances that learn from experience and computers that can make decisions. I have no knowledge of these matters but wonder what the future brings.

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e jaison

6/11/2008 1:33 PM EDT

is this a good topic to prepare a seminar on it??...am an electronics engineering student...and in search of a seminar topic on latest technologies...

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melanoman

7/11/2008 7:08 PM EDT

This is a brilliant step forward with a truly awful name. These things look like a comb. I'm going to call them combs. I look forward to the day that "memristor" is the answer to a trivia question and "comb" or some other easily pronounced replacement name is what we teach to the freshmen.

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PatrickBCC

7/25/2008 2:51 PM EDT

what are the implications of this new technology?

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