,Here's to me what I consider fascinating future news!
Vive La Memristance!
Sometimes it's good to have one eye looking towards the future. I read a very interesting article in a computer magazene whilst in Lake Garda. This article is a bit "Techie" but the fundamentals could be quite revolutionary for PC's.
Well without any further procrastination the story goes like this:
A fundamental new circuit element could lead to superfast memory, instant on PC's and a brain like computation. Clive Akass reports.
Researchers have created a forth fundamental circuit element that could supersede RAM & Flash Memory & could enable instant-on computers. It could also lead to computers that work more like our brains (I do hope not like mine LOL! cuz that is worrying).
The Obligatory Screenshot - Memristor in action 150 molecules wide
We need to go back in time to 1971 when the existence of this element was predicted in 1971 by a young university of Calafornia engineer, Leon Chua, in a brilliant revisting of basic circuitry. Most people (Me being not most) will be aware of Ohms law, giving the simple relationship between the voltage (V) across a resistence ® & the current (I) passing through it: V = IR. Less well known are similair relationships involving the two other classic two-terminal circuit elements, the capacitator & the Inductor. The Charge (Q) in a capacitance C is given by Q = CV: & the magnetic flux ([]) in an inductance (L) is [] = LI. Now at this juncture, one quick note of clarification this symbol [] is really a rectangle stood on end but my keyboard does not have this function unless I resort to ASCII which I do not want to do, so where you see "[]" symbol it's really a retangle.
Anyway Chua postilated a forth element displaying a similair relationship between charge and magnetic flux: [] = MQ where M represents something he called 'memory resistance' or memristance. The notional new element was accordingly called memristor.
These realtionships are more accurately described in calculus, the mathematics of change. This shows that, at any instant, Chua's equation is identical to Ohms Law: V = IM, with this strange quality called M acting like a pure resistance see below:
That Chua's Law ([] = MQ) and Ohms Law (V = IR) are closely related can be seen if you consider that the charge Q is the sum of the current I that has flowed, and that Faradays Law of Induction the Voltage V is equivelant to rate of change of Flux []. See http://tinyurl.com/39f6br for a fuller exposition of the mathematics (Yeh Right!).
The same will hold true of the next instant. Only this time the resistance of M will have changed. The resistance of a classic resistor is constant; The resistance of a memristor depends on the charge that has flowed into it. Stranger still, the 'memristor' "REMEMBERS" this value if you stop the current.
Chua's work was largely forgotten, except for specialists because no device exhibiting the effect could be found - or rather it was not recognised. Researchers investigating the electrical properties of nano-structures reported an odd behaviour (bit like my Psychiatrist, sorry MedEvil could not resist LOL!) over the years but no-one linked it to Chua.
Then Greg Snider, part of a team headed by Stan Williams at HP's Information and Quantum Systems Laboratory in Calafornia, pointed out that some of the results that they were getting mirrored those predicted by Chua.
"We all struggled to work out the microphysics involved involved," his colleague Donald Stewart told me "Stan Williams, myself and [fourth team member] Dmitri Strukov wrote down some equations, edited them and finally agreed they might be right. Then we saw the equations we had written were identical to those proposed by Chua."
If Memristance is so fundamental, why has it proved to be so elusive when even a simple piece of wire can be shown to have some degree of capacitance, resistance and inductance?
The reason is that the effect is only evident only at very small scales, where electric fields can be enormous (one volt across a nanometre is a field of strength is a Billion volts per metre).
The HP memristor consists of a 5nm film of titanium dioxide sandwiched between platinum contacts. The titanium dioxide, like silicon in transistors, is doped to make it more conductive But while transistors exploit the movements of charges within the doped silicon, entire dopant atoms shift when current flows in the memristor. And they stay where they are when it stops, which is what gives rise to the memory effect.
The effect works in both directions, "Lets say you push a charge through the memristor and the resistance doubles. If you push the same charge in the opposite direction it will have halved," said Stewart.
Switching times are of the order of a thousand times faster than FLASH, which is why there is so much interest in their use in memory. And like FLASH, they do NOT need to draw power to retain information.
This could lead to computers that simply freeze their current state when they are switched off and return instantly to that state when switched on again. Stewart points out that memristors are only one of several promising technologies competing to supersede FLASH. But while memristors could be used as simple digital switches, or even multi level memory cells, they can represent a continuous set of values and so can be used in analogue mode. One intriguing application would be to model the behavior of the synapes that link the neurons of the brain, which becomes more conductive the more they are used.
"The strength of the signal from the neuron is the same every time. How much gets through depends on the strength [conductance] of the synapse," said Stewart. This structure could be replicated to perform tasks like the pattern recognition, at which the the brain out performs digital computers.
The discovery of the memristor, anounced in Nature magazene, caused great excitement and threw the spotlight back on Chua, now a professor at Berkeley, and the remarkable inferences he drew from what began almost as a game.
Stewart said: "He (Chua) must be a pretty smart Guy."
I found this article fascinating I hope you find it as stimulating as I found it, not so much from a technical perspective but from the potential that exists for such technologies so much so that I have started to make my first Terminator but with my wifes voice instead of Arnies just to give my creation an added CHILL factor LOL! This technology is just around the corner & has far reaching implications linked to AI maybe we are in danger of playing too close to the wire sorry about the pun & resistance is futile to quote the BORG LOL! Well, Memristors all charged up & ready to "Rock n Roll"
G'Day Mateys,
Respect Guys,
ispy
