New Memristor Makes Low-Cost, High-Density Memory

KentuckyFC writes "A group of electronics engineers have discovered that a thin layer of vanadium oxide acts as a memristor, the fourth basic component of circuits after resistors, capacitors, and inductors that was discovered last year. At a critical temperature, a current passing through the layer causes it to change from an insulating state to a metal-like state, thereby changing its resistance (abstract). The effect lasts many hours — which is what makes the layer a memristor (a resistor with memory). The team says this could be scaled up to make resistive random access memory, or RRAM, at very low cost, from little more than layers of vanadium oxide."

Re:The flavour lasts forever.

[pines225]

The article suggests use as resistive RAM rather than a solid state drive. As long as it doesn't need to be a permanent memory element it might be possible to refresh periodically on a schedule that's safely less than the lifetime of the state transition, i.e. boost the phenomenon every hour or two. Shouldn't cause much of a power hit.

From the original announcment

[Baron_Yam]

I thought the more exciting announcement was that memristors could be tripled up to create transistors that were (despite being tripled up) still much smaller than a standard transistor.

Then, there were bits about them supporting more than just binary states, which would increase complexity and density yet again.

Denser memory may be the first pratical consumer product, but if the other possiblities work out, I'm pretty sure that memory will also be the least significant.

fourth type?

[Anonymous Coward]

I've seen this statement repeated about memristors. Many devices cannot be duplicated with L's, C's and R's (diodes, fuses, etc.). Those parts all have one thing in common, they are nonlinear and/or time varying. Memristors are not LTI and therefore not a "fourth type" of circuit element.

Re:This will make the spooks happy

[Anonymous Coward]

The situation is still somewhat rare that someone can go in and get all the data they like off your computer. They still need physical access to the computer before they can have a prayer at touching the data.

And heck, since DRAM is also capable of storing data for a couple of minutes after power is cut, you have the exact same problem as someone who has the new memresistor based ram.

Re:It is NOT a fourth basic component

[brendank310]

The GP was commenting on the fact that a memristor is not linear time invariant element. So it isn't as basic as the other 3. The other three can be analyzed using fairly simple analysis, while the memristor seems to introduce state to a circuit.
Circuits that are time linear, and time variant are more difficult to analyze on a broad scope than those that are LTI.

Re:It is NOT a fourth basic component

[Hodapp]

So according to you,

V dt = dphi = L di?

Or is this wrong? And if yes, why?

Well...
V dt = L di
(V dt)/dt = (L di)/dt
V = L di/dt ...which is the standard formula they give for inductors, isn't it?
Or did I totally miss your point?

Patentability

[kimvette]

. . . just posting this in the very unlikely chance that a competent USPTO employee (I know you're out there) is not only reading this thread but also is assigned related patents.

IMHO this kind of development is worthy of a patent; it includes a brand-new type of component, with no prior art in a single component appearing to exist, and a method by which it is manufactured.

Now, I expect patent trolls will start the patenting insanity with "it's a PDA, but with memristors" and "it's a phone, but with memristors" and "it's an instant-on PC, but with memristors" and in all of those cases I would say that the patent should not be allowed, because those are "innovations" which are obvious to those skilled in the art.

Also, the software to store to memristors should not be patentable. "method by which data is semi-permanently stored in a memristor-based storage device" should not be patentable, because that skill (putting data in memory or storage) is obvious to every literate computer user, let alone software engineers.

Re:From the original announcment

[BudAaron]

When I went through electronics school in the late 40s there were resistors, capacitors and inductors. The real news here is that we have a totally new circuit element and heaven only knows where that can take us.

The Memristor is NOT Fundamental

[sup2100]

The memristor is is just a way to model nonlinear circuit elements and is one of many components in a nonlinear expansion for circuit modeling. See this paper [ieee.org] by Leon Chua, the memristor's inventor. Note that in this paper the fourth element of the four element torus is negative resistance and not the memristor. All of the publicity over the memristor has been (sucessfull) marketing by some researchers at HP. .

From the talk page for the memristor on wikipedia [wikipedia.org]

"Resistance, Capacitance and Inductance are regarded as fundamental because to each there corresponds a different picture of what is going on with the energy. Resistance refers to the loss of energy to Joule heating. Capacitance refers to storage of energy in the electric field. Inductance refers to storage of energy in the magnetic field.

If memristance is the "fourth fundamental" circuit element then memristors must do something with the energy they are imparted other than turn it into heat, or store it in electric or magnetic fields. So what do memristor supporters have to say about this? nothing. This is not surprising, since the concept of memristance stems from a purely mathematical argument bent on taming the current/voltage relationships of nonlinear circuit elements. The concept of memristance was invented out of convenience to avoid dealing with frequency-dependent (time-dependent) resistance, inductance, and capacitance. Thus the memeristor is not "fundamental", unless in your book fundamental is synonymous with convenient."