Robot face lets slime mould show its emotional side - tech - 08 August 2013 - New Scientist

Robot face lets slime mould show its emotional side - tech - 08 August 2013 - New Scientist: Gale placed slime mould on a forest of 64 micro electrodes, along with some oat flakes. As the mould moved across the electrodes towards the food, it produced electrical signals, which Gale converted into sound frequencies...

Using a popular psychological model, the team was then able to assign each sound chunk an emotion...

Slime mould could make memristors for biocomputers

Slime mould could make memristors for biocomputers: The feeding fronds of the slime mould Physarum polycephalum turn out to have memory resistance – or memristance...

..."Slime mould can be used to perform all the logic functions that conventional computer hardware components can do," says Gale.

Her team is also exploring whether, in addition to number-crunching, slime mould's knack for finding the shortest path to nutrients can be used to design the most efficient circuit patterns for biocomputers.

Ferroelectric memristors may lead to brain-like computers

Ferroelectric memristors may lead to brain-like computers: In a new study, a team of researchers from France, the UK, and Japan has demonstrated that a device called a ferroelectric tunnel junction (FTJ) that experiences voltage-controlled resistance variation represents a new class of memristor. Due to the FTJ's quasi-continuous resistance variations exceeding two orders of magnitude, along with its rapid 10-ns operation speed, the device could one day serve as the basic hardware of neuromorphic computational architectures, or computers that function like brains...

"We have conceptualized, designed and realized a completely new type of memristor that performs as well as classical ionic memristors, but operates through an electronic mechanism," coauthor Manuel Bibes, a CNRS research scientist, told Phys.org. "While this should have clear advantages in terms of reproducibility, the key breakthrough is that our ferroelectric memristor behaves according to well-established physical models. This allows a precise understanding of the memristive response, and also opens the door for engineering memristive functions on-demand."

Superconductivity associated with fractal structure of nanoscale electron lines

Superconductivity associated with fractal structure of nanoscale electron lines:  Said Dahmen, “We decided to make histograms of the sizes of these regions and compare them with predictions from various models. We found they agreed with those from models that also had fingery regions in the bulk of the material—the agreement was striking.”

Carlson explained, “We noticed that the pattern of orientations of the nanoscale lines doesn’t depend on the scale of the image. The pattern looks the same whether we view the entire image, or whether we view smaller and smaller pieces of it—the pattern is fractal.

“Every fractal has its own set of characteristic numbers, as unique as a fingerprint. You might imagine that the characteristic numbers for a fractal which is happening only on the surface would be different from the characteristic numbers for a fractal which really originates from deep inside the material.

“When we studied the characteristic numbers of this fractal, we discovered telltale signs in its fingerprint that indicate this is not just a surface fractal.  Rather, it is coming from deep inside the material. We are seeing a 3-D fractal, which then intersects the surface of the material.”

A memristor true random-number generator

A memristor true random-number generator: ...However, with the CRRAM design, the memory cell conducts over a small area, so current flowing through it is especially sensitive to the capture and release of electrons that get temporarily trapped in the silicon dioxide film. This trapping and releasing is the random event that the new device relies on to produce random numbers.
“The natural fluctuation can’t be predicted..."

Intel Reveals Neuromorphic Chip Design� - Technology Review

Intel Reveals Neuromorphic Chip Design� - Technology Review: They base their design on two technologies: lateral spin valves and memristors. Lateral spin valves are tiny magnets connected via metal wires that can switch orientation depending on the spin of the electrons passing through them...

The icing on the cake, they say, is that spin valves operate at terminal voltages measured in milliVolts...

MAKE | How-To: Homemade Memristor

MAKE | How-To: Homemade Memristor: Fascinating video from Nyle Steiner, who reports on his experiments with simple homemade memristors made from what are, probably, Al-CuxSy-Cu and Al-PbS-Pb junctions. He describes the observations that led him to experiment with these systems and the results of his experiments, and then wraps up by drawing out a simple memristor demonstration circuit and showing its operation on-camera.

New Computer Chip Modeled on a Living Brain Can Learn and Remember | Popular Science

New Computer Chip Modeled on a Living Brain Can Learn and Remember | Popular Science: Built on 45 nanometer silicon/metal oxide semiconductor platform, both chips have 256 neurons. One chip has 262,144 programmable synapses and the other contains 65,536 learning synapses — which can remember and learn from their own actions...
 IBM's chip doesn't use a memristor architecture, but it does integrate memory with computation power — and it uses computer neurons and axons to do it. The building blocks are simple, but the architecture is unique..
"When a neuron changes its state, the state it is modifying is its own state, not the state of something else. So you can physically co-locate the circuit to do the computation, and the circuit to store the state. They can be very close to each other, so that cooperation becomes very efficient," he said...
It integrates memory with processor capability on a typical SOI-CMOS platform, using traditional transistors in a new design. Along with integrated memory to stand in for synapses, the neurosynaptic “core” uses typical transistors for input-output capability, i.e. neurons.

DVD alloys help make computers that think like us - tech - 12 July 2011 - New Scientist

DVD alloys help make computers that think like us: GST is known as a "phase-change" alloy, because of its ability to change its molecular structure from a crystalline to a disordered amorphous "phase" when heated...
Different areas within a tiny spot of GST can be crystalline or amorphous to differing degrees, which means it can store information across a much wider range of values than simply 0 or 1...
Wright's neuron is able to mimic this threshold firing because GST's electrical resistance drops suddenly when it moves from its amorphous phase to the crystalline. So incoming signals in the form of pulses of current are applied to the artificial neuron - and it is deemed to have fired when its resistance plummets...
GST's ability to change its resistance has allowed them to program it to dynamically modify the strength of the nanoscale artificial synapses they have built...
a system with 10^10 synapses would consume just 10 watts...

Memristor Processor Solves Mazes� - Technology Review

Memristor Processor Solves Mazes� - Technology Review: Pershin and Di Ventra begin by creating a kind of a universal maze in the form of a grid of memristors, in other words an array in which each node is connected to another by a memristor and a switch. This can be made to represent any regular maze by switching off certain connections within the array.

Solving this maze is then simple. Simply connect a voltage across the start and finish of the maze and wait. "The current flows only along those memristors that connect the entrance and exit points," say Pershin and Di Ventra. This changes the state of those memristors allowing them to be easily identified. The chain of these memristors is then the solution.

Sweat ducts make skin a memristor - life - 02 March 2011 - New Scientist

Sweat ducts make skin a memristor: The researchers attribute skin's memristor behaviour to sweat pores. Sweat contains positively charged ions such as sodium. When skin is exposed to a negative potential, the fluid at the bottom of the sweat pores is drawn upward. Although a thin layer of fluid always coats the inside of the cylindrical pore, this layer thickens as the sweat rises. As sweat is highly conductive, extra fluid rising to the surface increases skin's surface conductivity and thereby lowers its resistance if a subsequent potential is applied.

The longer skin is exposed to a negative potential, the lower the subsequent resistance, until it maxes out when sweat fills the pore. Conversely, a positive potential pushes the ions back, thinning the layer of sweat lining the pore walls and increasing the skin's resistance to current.

The Memristor � American Scientist

The Memristor � American Scientist
The favored layout for memristor memory is a crossbar structure, where perpendicular rows and columns of fine metal conductors are separated by a thin, partially doped layer of TiO2. In this way a memristor is formed at every point where a column crosses a row. Each bit in the memory is individually addressable by selecting the correct combination of column and row conductors. A signal pulse applied to these conductors can write information by setting the resistive state of the TiO2 junction. A later pulse on the same pair of conductors reads the recorded information by measuring the resistance...

One intriguing way to exploit analog memristors would be to build a machine modeled on the nervous system. In biological neural networks, each nerve cell communicates with other cells through thousands of synapses; adjustments to the strength of the synaptic connections is thought to be one mechanism of learning. In an artificial neural network, synapses must be small, simple structures if they are to be provided in realistic numbers. The memristor meets those requirements. Moreover, its native mode of operation—changing its resistance in response to the currents that flow through it—suggests a direct way of modeling the adjustment of synaptic strength.

Squishy Bio-Electronics Could Make Better Implants and Brain-Machine Interface Controls | Popular Science

Squishy Bio-Electronics Could Make Better Implants and Brain-Machine Interface Controls | Popular Science: A pair of grad students at North Carolina State University presented a paper last week describing a quasi-liquid diode whose electrodes are made of a gallium-indium alloy that is liquid at room temperature. Two hydrogel films are sandwiched between the electrodes — one is doped with an acid and the other holds an alkaline compound.
The interface between the electrodes develops a thin coating of gallium oxide, which creates resistance, as IEEE Spectrum explains. The electrode with the alkaline substance suppresses the formation of this skin. So, applying voltage changes the the thickness of this gallium oxide “skin” — negative voltage makes the oxide thinner, lowering the device’s resistance, and a positive voltage makes it thicker, producing greater resistance.

How DARPA Is Making a Machine Mind out of Memristors | Popular Science

How DARPA Is Making a Machine Mind out of Memristors | Popular Science: Their ability to both store and process information as it transfers charge (and to do so with far less power consumption) makes memristors more analogous to the neurons in the brain than any other previously developed electronic component, and they are small enough, cheap enough and efficient enough to someday be used to build computing platforms that function more like the brain: learning, making decisions, and even using a machine version of intuition to execute their roles.

Physicists Build Diode for Electromagnetic Waves - Technology Review

Physicists Build Diode for Electromagnetic Waves - Technology Review: The mathematics of electromagnetic wave propagation suggests that certain types of material should allow polarized waves to pass in one direction but not the other when bathed in a magnetic field. Engineers can readily build such a device but its effect is what physicists call linear, meaning that the amount of light you get out is proportional to the mount you put in...

A microwave passing through wires generates currents in each that tend to interact. At certain frequencies these currents re-reinforce or cancel out. Adding a nonlinear diode to one of the wires makes the effect of the metamolecule nonlinear too.

BBC News - Memristor revolution backed by HP

BBC News - Memristor revolution backed by HP: the potential benefits lie in the fact that memristors are "much simpler in principle than transistors".

"Because they are formed as a film between two wires, they don't have to be implanted into the silicon surface - as do transistors, which form the storage locations in Flash - so they could be built in layers in 3D"...

The joint effort between HP and Hynix will aim to develop memristor memory chips known as resistive random access memory (ReRAM), with an aim to have the first products ready by 2013.

Technology Review: Blogs: arXiv blog: Synaptic Behaviour Captured By New Memristor Circuit Design

Technology Review: Blogs: arXiv blog: Synaptic Behaviour Captured By New Memristor Circuit Design: "They say that in a single memristor connecting two neurons, the memristance decreases when a voltage is applied which increases the current which in turn causes the memristance to drop further, in a kind of positive feedback effect.

A lower memristance allows more current to flow so this certainly increases the strength of the connection as expected but there's a problem. The positive feedback effect means that later signals have a bigger effect on the connection than earlier ones, which is the opposite way round to the way real neurons connect, where earlier signals have the strongest effect.

Merrikh-Bayat and Bagheri have a simple solution: use two memristors in series."

Electronics 'missing link' brings neural computing closer

Computing with memristors

http://www.newscientist.com/article/mg20527515.900-electronic-marvel-brings-neural-computing-a-step-closer.html

Memristor minds: The future of artificial intelligence

http://www.newscientist.com/article/mg20327151.600-memristor-minds-the-future-of-artificial-intelligence.html

Amoeba inspires simple memory circuit

Memristor-like properties of the amoeba

http://www.newscientist.com/article/mg20026815.700-amoeba-inspires-simple-memory-circuit.html