Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Memristor — 4th Basic Element of Circuits

ScuttleMonkey posted more than 6 years ago | from the old-meets-new dept.

Hardware 291

esocid writes "Researchers at HP Labs have solved a decades-old mystery by proving the existence of a fourth basic element in integrated circuits that could make it possible to develop computers that turn on and off like an electric light. The memristor — short for memory resistor — could make it possible to develop far more energy-efficient computing systems with memories that retain information even after the power is off, so there's no wait for the system to boot up after turning the computer on. It may even be possible to create systems with some of the pattern-matching abilities of the human brain. Leon Chua, a distinguished faculty member at the University of California at Berkeley, initially theorized about and named the element in an academic paper published 37 years ago. Chua argued that the memristor was the fourth fundamental circuit element, along with the resistor, capacitor and inductor, and that it had properties that could not be duplicated by any combination of the other three elements."

Sorry! There are no comments related to the filter you selected.

Sure, it's neat (1)

taupin (1047372) | more than 6 years ago | (#23257314)

but when will we see products that use this?

Re:Sure, it's neat (2, Insightful)

eebra82 (907996) | more than 6 years ago | (#23257336)

Practical use, probably 15 to 20 years.

Insanely expensive prototypes with virtually no functionality in modern use, probably 4 to 10 years.

What a non-article (1, Insightful)

Moryath (553296) | more than 6 years ago | (#23257696)

According to their description, it's a memory cell that retains information without needing power. In other words, non-volatile RAM. It actually (according to their description) looks pretty darn similar to FeRAM.

Of course, to "Read" this stuff, you have to pass current through it to measure its resistance... so then you have to refresh it back to state... not sure how serious the power savings can be compared to simply improving the power required for other memory devices there.

In fact, the whole article is a bit misleading. They've come up with a new "memory element", just like how FeRAM and MRAM and now PRAM are new memory elements jockeying for position, and each of those comes with the same pie-in-the-sky pronouncements: computers that retain state when turned off without needing to cache to disk, lower power consumption/resiliency, neural networks, blabbity blah blah blah.

Some of the real jokes come later - pattern recognition, facial recognition, etc. Those come from either improving your software, or actually making a non-binary machine so that it's easier to express multiple states, not from just having a new way to store the same data set.

In a way, the stuff in this article reminds me a lot of people eating with their butts [wikipedia.org] .

Dangit... (1)

Moryath (553296) | more than 6 years ago | (#23257734)

got the wrong episode. [wikipedia.org]

Re:What a non-article (1)

owlstead (636356) | more than 6 years ago | (#23257884)

The difference between those memory technologies and this one seems to be that it could be integrated directly into the processor. "Cells" could retain memory without being powered. But that's just speculation by me.

Re:What a non-article (1)

drinkypoo (153816) | more than 6 years ago | (#23258066)

Of course, to "Read" this stuff, you have to pass current through it to measure its resistance... so then you have to refresh it back to state... not sure how serious the power savings can be compared to simply improving the power required for other memory devices there.

The simplicity of DRAM, with the lack of need for a refresh and therefore hopefully the speed of SRAM but with the ability to store data with the power off like NVRAM.

Sounds like it should be a faster and better alternative to DRAM, Flash RAM, SRAM, and NVRAM... and probably cheaper than DRAM (no need for refreshing should simplify even those devices.)

analog memory (4, Informative)

mo (2873) | more than 6 years ago | (#23258306)

The difference between a memristor and FeRAM is that because the memristor is constructed without using any transistors, it can be used as a kind of analog memory. Instead of just storing 1's and 0's, it's resistance is an analog value anywhere in the range of on and off. Of course you can still use it to store digital data, but the real fun will come when you interconnect these things to emulate the analog behavior of the brain. This is where the claim of pattern recognition and facial recognition come in. They're not actually talking about software there but the actual analog capabilities of circuitry built with memristors.

The other amazing thing about memristors is how small they are. The articles state that you can emulate a transistor by connecting a few memristors, and that transistor is smaller than any we have today. Also it states that the memristor actually performs better at smaller sizes. This really is neat stuff.

Re:Sure, it's neat (3, Funny)

ettlz (639203) | more than 6 years ago | (#23257354)

In about 200 years' time, when Evil returns.

Re:Sure, it's neat (0)

Anonymous Coward | more than 6 years ago | (#23257650)

Aziz, LIGHT!

might, might, might, could, could, could (2, Insightful)

EmbeddedJanitor (597831) | more than 6 years ago | (#23257744)

It is easy to make a whole lot of might and could style predictions for some discovery that works in a controlled lab environment, but it is a lot harder to deliver them in product form: reliable enough and low cost enough to be useful. The tecno development hiway is littered with technologies such as bubble memory that just never worked out.

We've had Non-volatile state storage for ages (eg. FeRAM and floating gates (as used in flash) and battery backed up RAM). State storage is only part of the picture.

Whatever the mechanism, freezing state is not sufficient to instantly boot a modern computer. Pretty much all modern computers have some communication with an external device that needs to be renegotiated and reconnected, be that a mouse, disk or network.

I prefer #2 (-1, Troll)

Anonymous Coward | more than 6 years ago | (#23257322)

A few years ago, while browsing around the library downtown, I had to take a piss. As I entered the john, a big beautiful all-American football hero type, about twenty five, came out of one of the booths. I stood at the urinal looking at him out of the corner of my eye as he washed his hands. He didn't once look at me. He was "straight" and married -- and in any case I was sure I wouldn't have a chance with him.

As soon as he left, I darted into the booth he'd vacated, hoping there might be a lingering smell of shit and even a seat still warm from his sturdy young ass. I found not only the smell but the shit itself. He'd forgotten to flush. And what a treasure he had left behind. Three or four beautiful specimens floated in the bowl. It apparently had been a fairly dry, constipated shit, for all were fat, stiff, and ruggedly textured. The real prize was a great feast of turd -- a nine inch gastrointestinal triumph as thick as a man's wrist. I knelt before the bowl, inhaling the rich brown fragrance and wondered if I should obey the impulse building up inside me. I'd always been a heavy rimmer and had lapped up more than one little clump of shit, but that had been just an inevitable part of eating ass and not an end in itself.

Of course I'd had jerkoff fantasies of devouring great loads of it (what rimmer hasn't?), but I had never done it. Now, here I was, confronted with the most beautiful five-pound turd I'd ever feasted my eyes on, a sausage fit to star in any fantasy and one I knew to have been hatched from the asshole of the world's handsomest young stud.

Why not? I plucked it from the bowl, holding it with both hands to keep it from breaking.

I lifted it to my nose. It smelled like rich, ripe limburger (horrid, but thrilling), yet had the consistency of cheddar. What is cheese anyway but milk turning to shit without the benefit of a digestive tract? I gave it a lick and found that it tasted better then it smelled. I've found since then that shit nearly almost does. I hesitated no longer. I shoved the fucking thing as far into my mouth as I could get it and sucked on it like a big brown cock, beating my meat like a madman. I wanted to completely engulf it and bit off a large chunk, flooding my mouth with the intense, bittersweet flavor. To my delight I found that while the water in the bowl had chilled the outside of the turd, it was still warm inside. As I chewed I discovered that it was filled with hard little bits of something I soon identified as peanuts. He hadn't chewed them carefully and they'd passed through his body virtually unchanged. I ate it greedily, sending lump after peanutty lump sliding scratchily down my throat. My only regret was the donor of this feast wasn't there to wash it down with his piss. I soon reached a terrific climax. I caught my cum in the cupped palm of my hand and drank it down. Believe me, there is no more delightful combination of flavors than the hot sweetness of cum with the rich bitterness of shit. Afterwards I was sorry that I hadn't made it last longer. But then I realized that I still had a lot of fun in store for me. There was still a clutch of virile turds left in the bowl. I tenderly fished them out, rolled them into my hankercheif, and stashed them in my briefcase.

In the week to come I found all kinds of ways to eat the shit without bolting it right down. Once eaten it's gone forever unless you want to filch it third hand out of your own asshole -- not an unreasonable recourse in moments of desperation or simple boredom.

I stored the turds in the refrigerator when I was not using them but within a week they were all gone.

The last one I held in my mouth without chewing, letting it slowly dissolve. I had liquid shit trickling down my throat for nearly four hours. I must have had six orgasms in the process. I often think of that lovely young guy dropping solid gold out of his sweet, pink asshole every day, never knowing what joy it could, and at least once did,bring to a grateful shiteater.

What the fuck was that? (0)

Anonymous Coward | more than 6 years ago | (#23257360)

Seriously, what the fuck?

Re:What the fuck was that? (0)

Anonymous Coward | more than 6 years ago | (#23257646)

Have you ever heard the expression, "I'd eat the corn out of her shit?" Anal/shit play is a huge turn on to a lot of people. I wouldn't eat shit out of a public toilet (especially a dude's shit), but I've rimmed a few girls. If she's clean, I prefer it over eating pussy.

Re:What the fuck was that? (0)

Anonymous Coward | more than 6 years ago | (#23258018)

I just threw up a little in my mouth...

Re:I prefer #2 (1)

Binder (2829) | more than 6 years ago | (#23257366)

My kingdom for some mod points!

Oh my... I think i actually went blind as soon as that hit the screen.

Re:I prefer #2 (0)

Anonymous Coward | more than 6 years ago | (#23257540)

Kill yourself freak.

Great! (2, Funny)

teddaman (854135) | more than 6 years ago | (#23257352)

One more thing to wipe after surfing porn.

but.. (0)

Anonymous Coward | more than 6 years ago | (#23257370)

Does it run Linux?
Does it blend?

Does it blend WHILE running Linux?

m$ will hate this (0)

Anonymous Coward | more than 6 years ago | (#23257382)

This would be a laugh. No way for windows users to reboot - the os would be effectively crippled in a few days. lol

Re:m$ will hate this (1)

jcr (53032) | more than 6 years ago | (#23257630)

No way for windows users to reboot

They could still re-install. ;-)

-jcr

Re:m$ will hate this (1)

SiriusStarr (1196697) | more than 6 years ago | (#23257976)

It's true. If computers evolve to the point where they are effectively never turned off, programmers are going to have to spend a lot more time focusing on memory leaks.

Just like a human brain? (4, Funny)

fahrbot-bot (874524) | more than 6 years ago | (#23257388)

develop ... computing systems with memories that retain information even after the power is off, so there's no wait for the system to boot up after turning the computer on. ... create systems with some of the pattern-matching abilities of the human brain.

As far as I know, human brains don't retain much information when the power is turned off and there's usually some trouble after the power is restored. Furthermore, I'm not sure how power-down information retention relates to pattern-matching abilities.

But what to I know, I had my brain off last night.

Re:Just like a human brain? (1)

SpeedyDX (1014595) | more than 6 years ago | (#23257512)

I guess it depends on what you mean by when the "power is turned off". Judging from your post, you probably mean falling asleep. But since the brain is far from powered off [wikipedia.org] when asleep, I suggest that the other meaning of powered off be used.

It's sort of difficult to restore power to that type of powering off of the brain. And when you do, I hear that the host's diet dramatically changes [theonion.com] .

Re:Just like a human brain? (4, Funny)

fahrbot-bot (874524) | more than 6 years ago | (#23257598)

Judging from your post, you probably mean falling asleep.

No, I meant my brain was really OFF. I'm a Zombie.
[ Where did you say you lived? ]

Re:Just like a human brain? (1)

ChrisMounce (1096567) | more than 6 years ago | (#23258236)

[you insensitive clod]

Re:Just like a human brain? (1)

mrbluze (1034940) | more than 6 years ago | (#23257682)

But what to I know, I had my brain off last night.
You may resist, you may refuse to remember, but VE HEF VAIZ OV MAKINK YU TOK!

one question (1)

Kr4u53 (955252) | more than 6 years ago | (#23257398)

If this was theorized 37 years ago, shouldn't we learn about it in physics?

To call it the forth element... (2, Insightful)

mkiwi (585287) | more than 6 years ago | (#23257400)

I wouldn't say this is the 4th basic circuit element- that is quite a stretch.

Basically you have Ohm's law which is v =Ri. There is a component for each variable: Capacitors for voltage, inductors for current, resistors for resistance. It is all there, in nice little differential equations.

Yes, this is a great discovery. But please stop with the sensationalist headlines. This is getting out of hand.

Re:To call it the forth element... (2, Interesting)

modmans2ndcoming (929661) | more than 6 years ago | (#23257556)

hmm... electronics component which has a function that can not be duplicated by any combination of the other 3.... seems pretty basic to me. Perhaps Ohm's Law needs a revision, or perhaps it does not cover memristors.

Re:To call it the forth element... (1)

HateBreeder (656491) | more than 6 years ago | (#23257834)

Actually, Ohms law is just a specific case of Gauss's Law - one of the four Maxwell Equations.

Re:To call it the forth element... (4, Informative)

Anonymous Coward | more than 6 years ago | (#23257576)

What are you talking about? V does not equate to capacitors any more then it equates to electric generators or batteries. And where on earth did you get inductance as i? In many cases capacitors and inductors behave fairly similarly (baring the fact that inductors have a charge time). If anything inductors relate to a delta i and not i directly.

Ohms law does not describe the basic componets of a circuit, it only provides a simply way to determine simple information about a simple circuit (Mainly a energy source, and a resistor). It has no room for capacitors or inductors. You need much higher math for that.

Umm... what? (1)

Chmcginn (201645) | more than 6 years ago | (#23257592)

Capacitors don't provide voltage, they resist a change in it. Ditto for inductors & amperage. Although I'll agree it's not the fourth element - it would be the fifth. A NP junction in its various forms would be the fourth.

Re:Umm... what? (1)

dgatwood (11270) | more than 6 years ago | (#23257700)

What a lame fifth element. There's not even a Leeloo.

From the paper itself (5, Informative)

dfedfe (980539) | more than 6 years ago | (#23257666)

Figure 1 in the paper explains it. The four fundamental circuit variables are current, voltage, charge, and magnetic flux. There are six ways of choosing two of these four, which correspond to differential equations relating the variables. Two of them are "given" in that charge is the time integral of current and magnetic flux the time integral of voltage: dq = idt. dphi = vdt.

As for the others, they are components. For instance, a resistor R fits in dv = Rdi. A capacitor C fits in as dq = Cdv. An inductor as dphi = Ldi, and a memristor fills in the missing dphi = Mdq.

Re:From the paper itself (1)

Chris Burke (6130) | more than 6 years ago | (#23257702)

Ah, well that makes sense then.

Re:To call it the forth element... (2, Informative)

Chris Burke (6130) | more than 6 years ago | (#23257674)

The only thing covered by Ohm's Law is the resistor, that being the "R" in V = iR.

For capacitors the equivalent law is i = C (dV/dt), and for inductors it's V = L (di/dt).

You can combine them all for an RLC circuit, but the result isn't Ohm's law.

 

Re:To call it the forth element... (0)

Anonymous Coward | more than 6 years ago | (#23257866)

You can if you use imaginary impedences:

Zr = R
Zl = j*omega*L
Zc = 1/(j*omega*C)

From wikipedia: [The memristor] behaves like a non-linear resistor

We have something like that, minus the memory stuff, it's called a diode. Just like the diode, we can't represent it with a simple impedence, so I would say that in that particular sense, it's not a "4th element".

Zero boot time (1)

jhoger (519683) | more than 6 years ago | (#23257404)

This sounds like a great advance. However, computers that don't need to be booted or that boot instantaneously is not new.

TRS-80 Color Computer, for example boots instantly since it runs from ROM unless you are using OS-9.

The TRS-80 Model 100 keeps its file system in RAM and has a separate NiCD to backup the RAM. It boots instantly. The backup lasts months in my experience (even today with old NiCd's).

And any computer can simply be left on... no boot time.

So there's nothing here that cannot be done with a mixture of existing tech, except use less overall power when doing it.

Re:Zero boot time (1)

drinkypoo (153816) | more than 6 years ago | (#23258088)

Both of those computers do jack diddly shit, the Amiga has half its OS in ROM and even when you reboot from the recoverable ramdisk (so you hit the disk for about a second) it still takes a few seconds for things to sort themselves out. Computers more complicated than a digital joystick need a little time.

Re:Zero boot time (1)

jhoger (519683) | more than 6 years ago | (#23258258)

Well you're wrong. I can do plenty of interesting applications with both. Text editing and terminal emulation is pretty useful and the Model 100 is very good at both.

But to conclusively disprove your point, just look at the Palm Pilot. It turns on instantly too.

Boot time is not a necessity.

I don't get it (1)

visualight (468005) | more than 6 years ago | (#23257412)

Based on the comments above me I'm not the only one who picked up less than nothing from the article...What is it and how does it work? This is less detailed than a Star Trek Particle description.

Re:I don't get it (1)

Otter (3800) | more than 6 years ago | (#23257616)

Article [nature.com] and commentary [nature.com] at Nature. (I'm not sure whether either or both are subscription-only.)

The bizarre characterization of this as a discovery instead of an invention originates in the paper itself.

Re:I don't get it (1)

Pinky's Brain (1158667) | more than 6 years ago | (#23257786)

The memristor stuff is largely bull, this seems to depend on a rather peculiar aspect of Titanium Dioxide. They are able push oxygen molecules between the surface of a normal layer and a N-type layer of Titanium Dioxide and get large swings in resistance that way.

... on the flip side (1)

vivin (671928) | more than 6 years ago | (#23257432)

Does this mean I will eventually not be able to use "try rebooting the system" (to try and solve a problem)? In all seriousness, I think this will make us rethink our problem-solving approach. Powering-off is a great way to "wipe the slate clean" as it were.

Would this also inspire new forms of malware/viruses/trojans that persist in memory even after the system is powered off?

And another thing... forensic computer evidence. I guess you could sort of tell what the user was last doing before they turned off the machine.

Depends on how all of this is going to be implemented anyways. Still, some interesting points to consider.

Re:... on the flip side (1)

26199 (577806) | more than 6 years ago | (#23257476)

Doesn't matter.

If memory is settable -- and that is certainly a requirement -- then it's possible to set it all to zero at the flick of a switch. Hence, rebooting.

Also: it's possible to recover the state of current RAM a surprising amount of time after the user switched off the machine. (Well, okay, tens of seconds, at least).

I suppose if it became a problem you could always encrypt it on powerdown...

Re:... on the flip side (1)

maxwell demon (590494) | more than 6 years ago | (#23257624)

Does this mean I will eventually not be able to use "try rebooting the system" (to try and solve a problem)? In all seriousness, I think this will make us rethink our problem-solving approach. Powering-off is a great way to "wipe the slate clean" as it were.

In most cases, a "warm reboot" (i.e. processor reset) gives exactly the same effect as a "cold reboot" (i.e. switching off and on again). Which proofs that you don't need to have clean memory for a reboot. After all, whatever is in memory doesn't matter when it's not read or executed.

Re:... on the flip side (1)

Shadow-isoHunt (1014539) | more than 6 years ago | (#23257964)

You already can, I can dump your RAM from my USB key already(After a reboot, even after removing the RAM from one computer and putting it in another) and go through for whatever I'd like, whether it's encryption keys, disk cache, or buffers from IM conversations. http://tourian.jchost.net/shadow/liveusb/boot.png [jchost.net] http://tourian.jchost.net/shadow/liveusb/memoryremenance.png [jchost.net] http://tourian.jchost.net/shadow/liveusb/memoryremenance-filecarving.png [jchost.net] http://citp.princeton.edu/memory/ [princeton.edu] http://mcgrewsecurity.com/projects/msramdmp/ [mcgrewsecurity.com]

Reminds me of a joke... (2, Funny)

Jonny 290 (260890) | more than 6 years ago | (#23257454)

An engineer, a physicist and a mathematician are staying in a hotel.
The engineer wakes up and smells smoke. He goes out into the hallway and sees a fire, so he fills a trash can from his room with water and douses the fire. He goes back to bed.
Later, the physicist wakes up and smells smoke. He opens his door and sees a fire in the hallway. He walks down the hall to a fire hose and after calculating the flame velocity, distance, water pressure, trajectory, etc. extinguishes the fire with the minimum amount of water and energy needed.
Later, the mathematician wakes up and smells smoke. He goes to the hall, sees the fire and then the fire hose. He thinks for a moment and then exclaims, "Ah, a solution exists!" and then goes back to bed.

Re:Reminds me of a joke... (1)

garett_spencley (193892) | more than 6 years ago | (#23257946)

Must have been one damned persistent arsonist.

Why would he not use an accelerant ?

Does this hotel not have smoke alarms ?

And why would none of them call the fire dept. and / or report the fire to the hotel management ?

Your story is full of holes.

Re:Reminds me of a joke... (1)

getnate (518090) | more than 6 years ago | (#23258294)

I think this one's more fitting:
A mechanical engineer, an electrical engineer
and a software engineer are traveling in an old
Fiat 500 (Bambino) when all of the sudden the car
backfires and comes to a halt.
The mechanical engineer says "Ah! It's probably a problem with the valves, or the piston!".
The electrical engineer says "Nonsense! It's most probably a problem with the spark plugs or the battery!".
The software engineer says "How about we all get out of the car, and get back in again".

I'll admit I don't understand the classification (2, Insightful)

Chris Burke (6130) | more than 6 years ago | (#23257468)

I don't understand what makes it a "fundamental" part of a circuit, while say a diode or MOSFET isn't. You can't make a transistor out of resistors, capacitors, and inductors... That's why it always showed up as the magical "voltage-controlled current source" in entry-level circuit analysis courses. I thought the three classic "basic" elements were because they were just the simplest.

Or maybe they're "basic" because every circuit (that's not superconducting), whether or not it contains semiconductors or more exotic stuff, has some amount resistance, capacitance, and inductance. Even if you don't want it, in which case you call it "parasitic". I don't think you're going to accidentally create two separate layers of titanium oxide.

So while I get why this discovery is totally awesome, I don't get what they mean by "fourth fundamental circuit element". Anyone got the skinny?

Re:I'll admit I don't understand the classificatio (1)

garett_spencley (193892) | more than 6 years ago | (#23257978)

Anyone got the skinny?

Yes but please don't tell anyone. I'm having a hard enough time trying to get girls to like me as it is.

Re:I'll admit I don't understand the classificatio (1)

Chris Burke (6130) | more than 6 years ago | (#23257988)

Well I could blab about it all I wanted and there's still little chance of a girl finding out, so I think you're safe.

Re:I'll admit I don't understand the classificatio (4, Informative)

moosesocks (264553) | more than 6 years ago | (#23258046)

This one took quite a bit of thinking, although this wikipedia article [wikipedia.org] summarizes it best.

A transistor may be approximated as a variable current source. Similarly, many applications of transistors are as "active" devices, which supply external power to the circuit being considered.

A diode is effectively nothing more than a voltage-controlled switch. In a DC circuit, it simply passes current through (with a small voltage drop that can be approximated by an inline negative voltage source).

Likewise, all transistors can be abstractly considered as networks of diodes. This is why they are inherently binary devices, and why computers "think" in binary.

The classical circuit elements (Resistor, Capacitor, Inductor) each fundamentally affect the electromagnetic properties of the electrons flowing through said circuit.

Resistors impede the flow of current; a capacitor is a current "bucket" that also blocks DC signals in AC circuits; and an inductor builds up a sort of inertia for the flow of current, through the creation of a magnetic field.

The distinction is hazy, but I think I can see it where it comes from.... when a diode/transistor does something, it affects of the "layout" of the circuit, rather than directly affecting the electrons flowing through it.

The memristor is extremely interesting, as it blurs the line between analogue components and solid-state devices, and provides exciting possibilities for the development of analogue computing and data storage.

Even more exciting is that they can already be made smaller than transistors, and two can be combined to create a device that functions analogous to a transistor.

Considering that we're quickly approaching the limits of Silicon-based technology, this invention may very well offer the key to the true "next generation" of electronic devices, and may very well be as significant to our generation as the transistor was to the previous. This is Nobel Prize-worthy stuff we're talking about.

Kudos to HP for supporting "true" R&D. They most definitely will be reaping the benefits of this one for years to come.

Re:I'll admit I don't understand the classificatio (1)

Komi (89040) | more than 6 years ago | (#23258304)

The distinction is hazy, but I think I can see it where it comes from.... when a diode/transistor does something, it affects of the "layout" of the circuit, rather than directly affecting the electrons flowing through it.

Not quite correct. A transistor does directly affect the electrons that flow through it. I'm particularly thinking of MOSFETs, which I work with. There's a gate that directly affects how much current will flow through the channel.

I think the distinction has to do with linearizing the circuit. When you decompose a transistor into a voltage controlled current source, you get a linear element. Rs, Ls, and Cs are already linear. But I don't get why the memristor should be considered a new fundamental circuit element. It doesn't sound linear. Actually it just sounds like a current controlled resistor. I'm sure it's quite useful, but I don't see why you can't break it into linear circuit components.

Re:I'll admit I don't understand the classificatio (1)

drinkypoo (153816) | more than 6 years ago | (#23258132)

Diodes and all types of transistors work on the same principle. If this doesn't, then it's something new. If it is, then it's just exploiting formerly misunderstood properties of a transistor. Resistors and capacitors, of course, are completely different from transistors; resistors are just harder to push electrons through and capacitors store them. They're fundamentally different beasts in that we are interested in totally different properties of each (although a transistor certainly has both resistance and capacitance, and a capacitor has resistance, and a resistance ostensibly has some capacitance... everything else seems to.)

Re:I'll admit I don't understand the classificatio (1)

Rob the Bold (788862) | more than 6 years ago | (#23258164)

I don't understand what makes it a "fundamental" part of a circuit, while say a diode or MOSFET isn't.

I think what the fundamental elements have in common is that they have a linear transfer function, whereas transistors and diodes are non-linear.

Re:I'll admit I don't understand the classificatio (5, Informative)

Anonymous Coward | more than 6 years ago | (#23258198)

I don't get what they mean by "fourth fundamental circuit element"

There are four fundamental circuit variables; current, voltage, charge, and flux.

We can define the relationships between charge and current and between flux and voltage. (charge as an integral of current, flux as an integral of voltage over time)

A resistor provides a function to relate voltage and current.
A capacitor provides a function to relate charge and voltage.
An inductor provides a function to relate flux and current.

Until now we did not know how to construct a passive device which would provide a function relating charge and flux. The only remaining combination of these fundamental variables.

Mod parent up. (1)

Chris Burke (6130) | more than 6 years ago | (#23258230)

That's a good explanation that ties together what I already knew about RLC circuits with the piece that was missing, thank you.

Re:I'll admit I don't understand the classificatio (1)

amirulbahr (1216502) | more than 6 years ago | (#23258234)

A memristor is a passive, two port element that "remembers" how much current has passed through it. That is, its resistance depends on how much current has previously passed through it.

Artificial memristors have been fabricated in labs using active elements (that require a power source, just like a transistor), to demonstrate its operation and potential application.

TFA is interesting, because this is the first time a real memristor has been demonstrated. i.e. it uses no active elements and requires no external power to actually behave like a memristor.

Re:I'll admit I don't understand the classificatio (0)

Anonymous Coward | more than 6 years ago | (#23258300)

Well, if I had to guess I would say they are commenting more on functionality than form of the basic devices. Using capacitors, inductors, and resistors sealed in a vacum tube will give you the voltage following voltage source (tube amplifier), as well as a rectifier (wikipedia has a nice illustration of a tube rectifier at http://en.wikipedia.org/wiki/Rectifier).

I grant you semiconductor devices are much better at those functions, hence why we use them, but their abilities weren't without precedent when they were created.

As far as the article goes I would take it with a grain of salt. This looks very familiar to the molecular memory from a few years back (I think also reported by HP labs, or possibly IBM), where it turned out instead of storing a charge in a molecule the researchers were just spot welding the connection leads together by putting too big a current accross the leads (sort of like flash memory, only it wore out much faster).

Punching a hole in the titanium dioxide layers with an overvolt would definatly change the resistance, the question is can you change it back, and how many times can you repeat the cycle with the same device?

Good news, everybody! (1)

Digi-John (692918) | more than 6 years ago | (#23257482)

I've just invented the memristor!

Another grand name from the creator of the finglonger.

"proved the existence" ?? (1)

l2718 (514756) | more than 6 years ago | (#23257490)

Repeat after me: the researchers constructed a membristor.

Somehow, I don't think these scientists really care about the abstract existence of memristors. Moreover, you can't prove the existence of something that didn't exist before you started. You might be able to proved the feasibility of such devices, but only in mathematics it may be appropriate to say you "proved the existence" of something when you actually have a construction.

4 down, 1 to go... (2, Funny)

Tumbleweed (3706) | more than 6 years ago | (#23257500)

and then we'll have Leeloo and her multi-pass! Totally cannot wait...

Re:4 down, 1 to go... (1)

owlstead (636356) | more than 6 years ago | (#23258020)

It's the fifth... element... /me passes out.

the four fundamental elements (1)

Virtex (2914) | more than 6 years ago | (#23257508)

So there you have it - the four fundamental elements are now earth, air, fire, and memristor. We never really wanted water in our computers anyway, so it's good to eliminate it (and don't even think about water cooling your systems - that's sacrilege).

New Scientist link with some more information (2, Informative)

DocTee (6393) | more than 6 years ago | (#23257530)

http://technology.newscientist.com/article/dn13812-engineers-find-missing-link-of-electronics.html

This is very interesting stuff. I wonder if these will ever be produced for amateur use, or if they'll only ever find their way into DRAM and such..

Another link with yet more information (EETimes) (2, Informative)

DocTee (6393) | more than 6 years ago | (#23257652)

Mod parent up (0)

Anonymous Coward | more than 6 years ago | (#23257752)

+5 real information

Re:Another link with yet more information (EETimes (1)

bar-agent (698856) | more than 6 years ago | (#23258016)

The analogy with Aristotle's Law of Motion and Newton's Second Law against circuit design theory (basically, charge:flux :: force:acceleration is correct, and charge:voltage :: force:velocity is wrong) is the most interesting thing in the EE Times article.

I'd love to hear comments about that.

Call me old quaint (1)

value_added (719364) | more than 6 years ago | (#23257532)

The possible uses outlined in the article inspire the imagination, but for my money, a technology that remembers everything presents a privacy risk too extreme to contemplate.

Re:Call me old quaint (1)

Warll (1211492) | more than 6 years ago | (#23257594)

You mean like Hard drives, Magnetic tape and flash memory? Oh and don't forget good old paper and rock.

Re:Call me old quaint (2, Interesting)

Chandon Seldon (43083) | more than 6 years ago | (#23258028)

Good: You're trying to recognize privacy problems.

Bad: You apparently don't understand the problem well enough to differentiate problems from non-problems.

Ummm..... (0)

Anonymous Coward | more than 6 years ago | (#23257570)

The memristor - short for memory resistor - could make it possible to develop far more energy-efficient computing systems with memories that retain information even after the power is off, so there's no wait for the system to boot up after turning the computer on.
Have you heard of this thing called FLASH?

Re:Ummm..... (1)

maxwell demon (590494) | more than 6 years ago | (#23257774)

Not to mention MRAM [wikipedia.org] , FeRAM [wikipedia.org] , PRAM [wikipedia.org] , ...

Core memory all over again! (0)

Anonymous Coward | more than 6 years ago | (#23257622)

Didn't we have the same thing in the 50's and 60's with core
memory? Manufacturers were known to even do the IPL (initial
program load), then power the machine off, crate it, ship it, and
at the receiving end, you'd turn the power on and it was ready
to run right away -- already IPL'd. (Yes, the cores would often
not shift during cross country shipping).

Re:Core memory all over again! (1)

maxwell demon (590494) | more than 6 years ago | (#23257784)

Wasn't core dumped?

Great an cool tech that will windows suck more as. (0, Troll)

Joe The Dragon (967727) | more than 6 years ago | (#23257642)

Great an cool tech that will windows suck more as it will stay in ram and not fully unload it self when you shut down.

Re:Great an cool tech that will windows suck more (0)

Anonymous Coward | more than 6 years ago | (#23257760)

No, think linux suck less more mac os X as computer turned on all day night even more.

Advantage over Flash RAM? (1)

RKBA (622932) | more than 6 years ago | (#23257726)

PROM's, EPROM's, EEPROM's, FLASH, etc., have been around for a very long time. Is this "memresistor" different/better because it's denser and cheaper to manufacturer? Unless I missed it, the article never cites any advantage over existing non-volatile memory technologies.

Re:Advantage over Flash RAM? (1)

skelly33 (891182) | more than 6 years ago | (#23257960)

Just a guess from what I read, but for one, I would think that where the memory cells of current storage devices require several inter-operating bits and pieces, a memory cell of the future using this technique might pack multiple times the storage capacity into the same chip due to extremely reduced complexity.

I also wonder if something like this could be used, say, in the manufacture of LED displays where each pixel has dedicated state information. Then we could send packetized bursts of change information to the display to update pixels and have the display natively retain the image even without a constant, scanning signal. How about attaching a monitor to any low power, portable device with wireless USB4.0 capability rather than requiring a demanding signal generator? (Perhaps this is already a potential with current technology?)

Anyway, as the artice mentions, state-retaining RAM, where DRAM is considerably faster than Flash, could get you instant-on computing without booting. Ever. CF isn't fast enough to operate as system memory - that's why it's not used that way now.

Re:Advantage over Flash RAM? (1)

Wo1ke (1218100) | more than 6 years ago | (#23257980)

It's denser than traditional HDDs and has the data recovery speed of RAM, so yeah. Seems fairly different/better.

Re:Advantage over Flash RAM? (1)

WarJolt (990309) | more than 6 years ago | (#23258054)

Flash must be written by the block. In binary you zero everything out in the block and write all the ones or visa versa.

It's slow. It doesn't behave like RAM. It's also got a max number of writes typically expressed in MAX-number of erase cycles.

Don't know much all the PROMS, but the ones that I'm familiar with are slow.

Re:Advantage over Flash RAM? (1)

espiesp (1251084) | more than 6 years ago | (#23258112)

Well... PROM isn't Erasable.
EPROM isn't erasable except with ultraviolet light.
EEPROM is slower than a ball rolling up hill.
And FLASH is only marginally faster when compared to modern DRAM.
So, I'd say it offers many distinct advanatages.

Re:Advantage over Flash RAM? (1)

owlstead (636356) | more than 6 years ago | (#23258118)

Well, I don't see any reasons why it would not be as fast as SRAM or why it wouldn't be possible to integrate it directly within the CPU. We have chips that contain flash alright, but not right within the core of the CPU. Think registers that are ready for use even after being powered down. This also makes it possible to create cells that retain their information locally even when not operating. At least, that is my interpretation of what they are saying here.

What I don't understand is the reason why it could not be integrated into CPU design almost directly. Circuit design may be expensive, but if this kind of technology can be created in a standard fab, I wonder how long it will take until we see this in actual products.

a quick read (1)

bigmo (181402) | more than 6 years ago | (#23257772)

suggests that it's something like an "analog" digital potentiometer. There was some experimentation for a while (and I guess still is) using analog computers and circuits that work like this.

The first computer I ever built was simply 3 potentiometers and an analog milliammeter (circa 1969). Setting two of the pots to particular positions on a dial would cause the meter to move up. The third pot was turned until the meter went back to zero. The dial on that pot then showed the "answer". It could be used to do simple multiplication and division.

I suppose those pots did in fact hold a sort of "memory". The memristor would probably be most useful for sensors and the type of "computation" I mentioned above.

Capacitors have memory? (1)

copdk4 (712016) | more than 6 years ago | (#23257918)

pardon my ignorance in digital electronics - I thought capacitors "store" charge for a while with some decay rate, can this be comparable to the function of "memory"?

Re:Capacitors have memory? (1)

WarJolt (990309) | more than 6 years ago | (#23258010)

In the right conditions a capacitor could store a charge for a long time, but it does leak. The problem is that once it's discharged it loses it's state.

You'd want to be able to store a state and figure out what the state is without changing the state.

Please no more! (1)

Ceiynt (993620) | more than 6 years ago | (#23257952)

Sweet gravy no. I'm having a hard enough time learning inductors/capacitors. Good thing this kind of stuff does hit university for a good 15+ years.

A much better article (1)

bobetov (448774) | more than 6 years ago | (#23257962)

Here: CNet Writeup [news.com]

Discussion of why a memristor is new, and more about how it works.

Doesn't it look like..... (1)

PipsqueakOnAP133 (761720) | more than 6 years ago | (#23257966)

The caption makes it sound to me like...well... a MOSFET. but that's just cuz the caption was written poorly.

The theory makes it sound to me like.... well... a Flash memory cell.

So what's the big deal?

What do they mean by basic??? (1)

camperslo (704715) | more than 6 years ago | (#23258036)

If they mean passive components that function with voltage other than input signals, or devices with only two connections, shouldn't they count diodes? And what integrated circuit actually uses parasitic inductance (that from the bonding wires connecting the chip)? The only semi-real inductance-for-a-purpose I've seen in a monolithic chip isn't available without the chip being powered, and is essentially synthesized by use of capacitance in the feedback loop of an inverting amplifier.

And if we're cheating and using power to simulate inductors, haven't we already got memistors of sorts? Things like simple latching flip-flop behavior, or memory on the capacitance of stored gate charge? Or something that has memory with power off, as in flash-memory.

If they want to invent a new basic device with memory I've got one. Call it a fliptode.
It's like a diode, but by applying a pulse above a specified voltage in the non-conducting direction it flips the anode and the cathode around. I suppose a third programming pin could be used instead.

Trivia bits - A long time ago Apple used various combinations of grounding three connector pins to identify the operating resolution of a monitor. Eventually they needed more combinations. They got more, and maintained backwards compatibility, by allowing diodes between the pins, with the polarity choices (diode direction) also adding combinations.

Isn't a fuse a write once memistor? That's more or less what field-programmmable ROMs contained.

For more fun do something with a chip full of tunnel diodes!

If this is all too complicated, bring back core memory

Resistivity? (1)

Brain_Recall (868040) | more than 6 years ago | (#23258068)

The article is very light on actual details, but you could already do this to some degree.

Resistance of metals can increase with the temperature of the metal (see http://en.wikipedia.org/wiki/Resistivity [wikipedia.org] ). With that, you could try this at home. Take a length of wire, and thermally insulate it. Put a lot of current through it to heat it up. Wait. Read the resistance of the wire later on. The resistance of the wire now is slightly higher than it was (resistivity is rather small, and you would probably only see a tenth of an ohm difference). A higher resistance means a "one" was previously written to it. A lower, "normal", resistance means it was a zero. So, to write a one, dump lots of current into it. To write a zero, let it cool down.

Of course, this is neither fast or power efficient, but it works to some degree (pun!).

Am I missing something? (1)

IorDMUX (870522) | more than 6 years ago | (#23258072)

Okay, I RTFA'd, but I still don't get it. Their summary states:

When a current is applied to one, the resistance of the other changes.

Now, if I'm correct:

A) This requires current to flow through the first wire, so where's the memory?
B) Aside from the probably-more-linear relationship, how is this different from JFET's or BJT's?

I mean, the transistor is a device where you run a current or voltage to point A, changing the resistance between points B and C. Can someone explain the difference?

But... what is it? (1)

McGregorMortis (536146) | more than 6 years ago | (#23258134)

The linked article, and even the Wikipedia page about it, are leaving me very puzzled.

The fundamental circuit elements are all "fundemental" because they have very simple mathematic functions that describe their behaviour.

For resitors, it's just Ohm's law: V = I*R

For capacitors and inductors, there are integrals involved (which, for you paranoiacs, means they "remember" the past, just like this memristor thing).

Capacitor: V = 1/Capacitance * Integral( I )
Inductor: I = 1/Inductance * Integral( V )

Inductors can be seen as the "dual" of capacitors (just swap voltages and currents in the equations.) Resistance can be seen as having a "dual" of conductance (again, swap voltages and currents).

So, where does this "memistor" fit in? What is its mathematical function? Does it have a dual? Perhaps a "forgetistor"?

The difference (1)

ZonkerWilliam (953437) | more than 6 years ago | (#23258140)

There's a difference between the memristor and flip-flops and any other device that mimics it. This is one device, not made up of transistors or capacitors, simplifying a circuit considerably. Also it scales beautifully to the nanometer size, allowing for smaller, simpler fast memory without need of capacitors.

Non-linear? (1)

usul294 (1163169) | more than 6 years ago | (#23258190)

It seems to me from reading a few articles, that this is a non-linear device. For the record I'm just finishing EE junior year. It seems the applications for these devices are like flip-flops (a la the memory talk) and to act like axons. Using analog analysis on flip flops shows that they are non-linear. (I thought through a few different logics, CMOS, TTL, and diode logic). Axons, as far as I can tell from the internet and Carver Mead's book: Analog VLSI and Neural Systems, are non-linear as well. Why is linearity important? Well resistors, inductors and capacitors are linear. Diodes are non-linear and aren't considered basic circuit elements. Linearity, by the way, means that if I input signals x1 and then x2 into a circuit, I get y1 and then y2 as outputs; then I put in a third signal, A*x1 + B*x2, the output is A*y1 + B*y2. Though honestly, without specific equations for the device, I couldn't be sure.

What happens when Windows locks up? (0)

Anonymous Coward | more than 6 years ago | (#23258262)

Does the computer stay locked up when we reboot?
Load More Comments
Slashdot Login

Need an Account?

Forgot your password?