‘Wet’ Computer Server
The University of Leeds is testing Iceotope, a liquid-cooled computer server in the hopes of slashing the carbon footprint of the Internet.

While most computers use air to cool their electronics, all of the components in the new server are completely immersed in liquid with the power-hungry fans replaced by a silent liquid cooling process that relies on the natural convection of heat.

Its designers calculate that the server cuts energy consumption for cooling by between 80 and 97 percent.

While the information industry enjoys an image of hyper efficiency and environmental friendliness, all internet use relies on remote servers, which are usually housed in large data centers that must be constantly cooled to remain operational. The reality is that the mobile apps, networked devices and 24-hour internet access on which we have come to rely are very energy hungry.

The server was designed and built by UK company Iceotope in conjunction with a team of researchers from the University of Leeds’ School of Mechanical Engineering. The first production system has now been installed at the University after two years of testing prototypes.

The team used computational fluid dynamics to model how the coolant flows through the new server’s components. The liquid is more than 1,000 times more effective at carrying heat than air. The non-flammable liquid coolant, called 3M Novec, can be in direct contact with electronics because it does not conduct electricity.

There is no equivalent of the noisy fans required by traditional computers and the server does not require an elaborate pump to move the coolant over its components. Instead, a simple low energy pump, located at the bottom of the cabinet, pumps a secondary coolant (water) to the top where it cascades down throughout all 48 modules due to gravity.

The secondary coolant terminates at heat exchangers within the cabinet for transfer of heat to a third and final coolant, on an external loop, taking the heat away for external cooling or reuse.

The third coolant can be drawn from “grey water” sources such as rainwater or river water, further reducing the environmental impact of the server. Because of the high cooling efficiency of the system, the output water can reach temperatures of up to 50 degrees Centigrade, which can be used for heating and other uses.

The Iceotope system uses 80 watts of power to harvest the heat from up to 20 kilowatts of ICT use. The server also does away with the need for ancillary data centre facilities such as computer room air conditioning units, humidity control systems and air purification, the researchers added.

Molecules Into Microtubes
A team of researchers at Washington University in St. Louis unexpectedly found the mechanism by which tiny single molecules spontaneously grow into centimeter-long microtubes by leaving a dish for a different experiment in the refrigerator.

Once the researchers saw that the molecules had become microtubes, they set out to find out how. To do so, they spent about six months investigating the process at various length scales (nano to micro) using various microscopy and spectroscopy techniques.

What they found was that they could actually watch the self-assembly of small molecules across multiple length scales, and for the first time, stitched these length scales to show the complete picture. This hierarchical self-organization of molecular building blocks is unprecedented since it is initiated from a single molecular crystal and is driven by vesiclular dynamics in water, the researchers said.

This approach of making nano- and microstructures and devices is expected to have numerous applications in electronics, optics and biomedical applications.

The team used small molecules p-aminothiophenol (p-ATP) or p-aminophenyl disulfide added to water with a small amount of ethanol. The molecules first assembled into nanovesicles then into microvesicles and eventually into centimeter-long microtubules. The vesicles stick onto the surface of the tube, walk along the surface and attach themselves, causing the tube to grow longer and wider. The entire process takes mere seconds, with the growth rate of 20 microns per second.

The researchers found the mechanism by which tiny single molecules spontaneously grow into centimeter-long microtubes by leaving a dish for a different experiment in the refrigerator.

Organic Single-Component Conductor
While organic materials are often used as insulators, for example as the insulating coating of a wire, the field of organic electronics aims to develop organic materials that are highly conductive, similar to copper wire.

Single-component organic conductors that have been developed so far are semiconductors with room-temperature conductivities of 10^-6～10^-1 Scm^-1 because of large Coulomb repulsion between the electrons and small molecular interactions.

A team of researchers at the Institute for Solid State Physics, the University of Tokyo, has developed a new type of purely organic single-component conductor with record conductivity at room temperature (19 Scm^-1), composed of electrically neutral and symmetric molecular units, where the charge is widely delocalized. The assembled units form two-dimensional conducting layers which afford the metallic state under low pressure of around 10 katm.

This material has the highest room-temperature conductivity (19 Scm^-1) and transitions into a metallic state at the lowest pressure (～10 k atm) yet achieved among purely organic single-component conductors, the researchers asserted.

Collaborative work with other teams showed the newly developed, highly conductive organic single-component material is composed of highly symmetric molecular units linked by strong hydrogen bonds to form two-dimensional conductive layers.

Structure of the molecular unit and electrical resistivity in the purely organic single-component conductor. (Source: University of Tokyo)

Organic materials are generally soluble and therefore can be applied to printed electronics. One anticipated use of this material is as a next-generation organic electronic material, for example, for single-component organic wiring.

~Ann Steffora Mutschler

Electric Jell-O

With potential applications ranging from energy storage to medical sensors and biofuel cells, researchers at Stanford University have invented a printable, electrically conductive gel.

The research team at Stanford said the gel — created by Stanford chemical engineering associate professor Zhenan Bao, materials science and engineering associate professor Yi Cui and members of their labs  –  is quick and easy to make, can be patterned onto surfaces with an inkjet printer and demonstrates unprecedented electrical performance.

The material is a kind of conducting hydrogel – a jelly that feels and behaves like biological tissues, but conducts electricity like a metal or semiconductor. This combination of characteristics holds promise for biological sensors and futuristic energy storage devices, but has proven difficult to manufacture until now.

The gel was made by binding long chains of the organic compound aniline together with phytic acid, found naturally in plant tissues, which is able to grab up to six polymer chains at once, making for an extensively cross-linked network.

Rewriting Quantum Chips with Light

Using a beam of light, researchers from The City College of New York (CCNY) and the University of California Berkeley (UCB) controlled the spin of an atom’s nucleus in order to encode information.

The technique could pave the way for quantum computing, a long-sought leap forward toward computers with processing speeds many times faster than today’s.

Current electronic devices are approaching the upper limits in processing speed, and they rely on etching a pattern into a semiconductor to create a chip or integrated circuit. These patterns of interconnections serve as highways to shuttle information around the circuit, but there is a drawback in that once the chip is printed it can only be used one way.

The research team found the remedy for these problems in the emerging sciences of spintronics and quantum computing and developed a technique to use laser light to pattern the alignment of “spin” within atoms so that the pattern can be rewritten on the fly, which could one day lead to rewritable spintronic circuits.

However, attempts at using electrons for quantum computing have been plagued by the fact that electron spins switch back and forth rapidly, making them very unstable vehicles to hold information. To suppress the random switching back and forth of electrons, the researchers used laser light to produce long-lasting nuclear spin “magnets” that can pull, push, or stabilize the spins of the electrons. They did this by illuminating a sample of gallium arsenide with a pattern of light, much as lithography etches a physical pattern onto an IC. The illuminated pattern aligned the spins of all the atomic nuclei, and, thus, their electrons, at once, creating a spintronic circuit.

The probe head used to send radio-frequency pulses onto the coil used for pulsed spin manipulation of a gallium arsenide (semiconductor) sample. (Source: UC Berkeley and CCNY)

–Ann Steffora Mutschler

Cheap, Efficient Printed Electronic Devices

Powerful X-rays that can see down to the molecular level of organic materials used in printable electronics have revealed in new detail how to achieve high-performance transistors and solar cells with polymers—and why some materials perform better than others. These findings could lead to cheaper, more efficient printable electronic devices, according to a team of researchers at UC Santa Barbara.

Published in the journal Nature Materials, “This work is exciting because it helps reveal in new detail how we can achieve high performance transistors and solar cells with polymers,” explained UC Santa Barbara professor of materials Michael Chabinyc, who, with UCSB chemistry graduate student Justin Cochran and North Carolina State physicists Harald Ade and Brian Collins, set out to find out which materials and which processing steps worked better, in what is still a largely trial-and-error process for manufacturers of printable electronics. The effort also involved collaboration with an international team, including researchers from Monash University in Australia and Univeristät Erlangen-Nümberg in Germany.

Until recently, the process of selecting the organic conductive molecules to be deposited onto surfaces and what steps to take in order to improve their performance was something of a mystery as some materials and treatments worked better than others. “In transistors, we found that as the alignment between molecules increased, so did the performance,” Collins said. “In the case of the solar cells, we discovered alignment of molecules at interfaces in the device, which may be the key to more efficient harvesting of light. For both, this was the first time anyone had been able to really look at what was happening at the molecular level.”

The researchers said they hope this new technique will provide a better perspective into the nature of organic materials used in printed electronics and give researchers and manufacturers greater insight into the fundamentals of these materials since understanding how these materials work can only lead to improved performance and better commercial viability.

Continuing Moore’s Law With Multiblock Polymers?

In a move that seems like it could allow Moore’s Law to continue scaling, Intel is partnering with researchers also at UC Santa Barbara to develop multiblock polymers that will enable patterning of microelectronic devices at finer scales and lower cost.

With advances in polymer chemistry and a wide variety of monomer constituents to choose from, the world of multiblock polymers is wide open as these polymers can result in an astonishing array of materials, customizable to almost any specification, according to UC Santa Barbara scientists Glenn Fredrickson and Kris Delaney. However, the researchers caution that the flood of options could be overwhelming without a theoretical framework to guide research. Their paper, “Multiblock Polymers: Panacea or Pandora’s Box?” appears in the latest edition of the journal Science.

Polymers are large molecules comprised of repeating sequences of monomers. When more than one monomer type is present and the dissimilar monomers are organized and chemically bound into blocks, the resulting multiblock polymers can serve as the basis for a multitude of materials, to be used in applications as diverse as tennis shoes and solar cells. Scientists can create materials using monomers from a variety of sources, from petroleum to renewable feedstocks such as sugar or cellulose.

Multiblock copolymers can self-assemble into nanometer-sized domains, and therefore can exhibit remarkable combinations of properties, such as soft, strong, and elastic –– as in tennis shoe soles or skateboard wheels. For higher-tech applications, multiblock polymers could enable patterning of microelectronic devices at finer scales and lower cost.

The problem has become the sheer number of possible combinations for these monomers so the researchers suggest an approach that addresses materials performance needs by combining predictive computer simulation methods with advanced synthetic and structural characterization tools.

“Our simulation methods for predicting the self-assembled structures of multiblock polymers are quite advanced, and we are getting better at relating those nano-structures to the properties of the material. Multiblock polymers are extremely versatile—there is enormous latitude of design freedom, and it’s very promising in terms of developing materials with truly unique properties,” Fredrickson added.

The research team also included scientists from the University of Minnesota and the University of Texas.

—Ann Steffora Mutschler