Big step toward using light instead of wires inside computers.

Stanford Univ. engineers have designed and built a prism-like device that can split a beam of light into different colors and bend the light at right angles, a development that could eventually lead to computers that use optics, rather than electricity, to carry data.

They describe what they call an "optical link" in an article in Scientific Reports.

The optical link is a tiny slice of silicon etched with a pattern that resembles a bar code. When a beam of light is shined at the link, two different wavelengths (colors) of light split off at right angles to the input, forming a T shape. This is a big step toward creating a complete system for connecting computer components with light rather than wires.

 "Light can carry more data than a wire, and it takes less energy to transmit photons than electrons," said electrical engineering Prof. Jelena Vuckovic, who led the research.

In previous work her team developed an algorithm that did two things: It automated the process of designing optical structures and it enabled them to create previously unimaginable, nanoscale structures to control light.

Now, she and lead author Alexander Piggott, a doctoral candidate in electrical engineering, have employed that algorithm to design, build and test a link compatible with current fiber optic networks.

Creating a silicon prism 

The Stanford structure was made by etching a tiny bar code pattern into silicon that split waves of light like a small-scale prism. The team engineered the effect using a subtle understanding of how the speed of light changes as it moves through different materials.

What we call the speed of light is how fast light travels in a vacuum. Light travels a bit more slowly in air and even more slowly in water. This speed difference is why a straw in a glass of water looks dislocated.

A property of materials called the index of refraction characterizes the difference in speed. The higher the index, the more slowly light will travel in that material. Air has an index of refraction of nearly 1 and water of 1.3. Infrared light travels through silicon even more slowly: it has an index of refraction of 3.5.

The Stanford algorithm designed a structure that alternated strips of silicon and gaps of air in a specific way.  The device takes advantage of the fact that as light passes from one medium to the next, some light is reflected and some is transmitted. When light traveled through the silicon bar code, the reflected light interfered with the transmitted light in complicated ways.

The algorithm designed the bar code to use this subtle interference to direct one wavelength to go left and a different wavelength to go right, all within a tiny silicon chip eight microns long.

Both 1,300-nm light and 1,550-nm light, corresponding to C-band and O-band wavelengths widely used in fiber optic networks, were beamed at the device from above. The bar code-like structure redirected C-band light one way and O-band light the other, right on the chip.

Convex optimization

The researchers designed these bar code patterns already knowing their desired function. Since they wanted C-band and O-band light routed in opposite directions, they let the algorithm design a structure to achieve it.

"We wanted to be able to let the software design the structure of a particular size given only the desired inputs and outputs for the device," Vuckovic said.

To design their device they adapted concepts from convex optimization, a mathematical approach to solving complex problems such as stock market trading. With help from Stanford electrical engineering Prof. Stephen Boyd, an expert in convex optimization, they discovered how to automatically create novel shapes at the nanoscale to cause light to behave in specific ways.

"For many years, nanophotonics researchers made structures using simple geometries and regular shapes," Vuckovic said. "The structures you see produced by this algorithm are nothing like what anyone has done before."

The algorithm began its work with a simple design of just silicon. Then, through hundreds of tiny adjustments, it found better and better bar code structures for producing the desired output light.

Previous designs of nanophotonic structures were based on regular geometric patterns and the designer's intuition. The Stanford algorithm can design this structure in just 15 minutes on a laptop computer.

They have also used this algorithm to design a wide variety of other devices, like the super-compact  "Swiss cheese" structures that route light beams to different outputs not based on their color, but based on their mode, i.e., based on how they look. For example, a light beam with a single lobe in the cross-section goes to one output, and a double lobed beam (looking like two rivers flowing side by side) goes to the other output. Such a mode router is equally as important as the bar code color splitter, as different modes are also used in optical communications to transmit information.

The algorithm is the key. It gives researchers a tool to create optical components to perform specific functions, and in many cases such components didn't even exist before. "There's no way to analytically design these kinds of devices," Piggott said.

Siemens launches new low-voltage Simotics standard motors with highestefficiency class.

Siemens UK and Ireland has taken another step in energy efficiency with the launch of IE4, its new Simotics low-voltage motors based on the highest efficiency class technology currently available, to help UK plants meet stringent energy saving standards.

The IE4 motors are from the Simotics GP and Simotics SD series and offer up to 14 per cent higher efficiency than the IE1 portfolio, enabling users to achieve significant energy savings, as well as reduce associated operation and maintenance costs.

Designed to DIN EN 50347 Standard, the IE4 can easily replace existing IE1, IE2 or IE3 motors. For example, Simotics low voltage IE4 motors are suitable for use in pump, fan and compressor applications, as well as many more industrial applications.

Based on the 1LE1 platform, the highly-efficient IE4 motors are available in aluminium housing (Simotics General Purpose), with a range from 2.2 to 18 kW, as well as cast-iron housing (Simotics Severe Duty) offering a range of 2.2 to 200 kW, with two and four-pole versions available.

The motors can be operated directly on-line or converter fed, which also results in greater flexibility, particularly in retrofit projects. Since the standard output and shaft height assignment have been retained for the IE4 version, it is easy to replace the motors.

Muhammad Haroon at Siemens UK & Ireland, comments: “In view of the increasingly stringent energy saving standards, not only within the EU but globally, the launch of our IE4 series enables industrial plants to equip themselves for the future, while making substantial savings on energy.

The Siemens IE4 range is great for retrofit applications as the shaft height stays the same and offers greater flexibility as it can be used for line operation (DOL) as well as with a variable speed drive. It represents the development of our SIMOTICS 1LE platform and everything about the series, from the housing design to output, has all been designed to deliver the highest levels of efficiency and ease of application.”

Simotics motors are suitable for use in all industries, but particularly in the chemicals, oil and gas, water/wastewater, mining and heating, ventilation and air conditioning sectors. The motors’ asynchronous design constitutes a reliable technology for pump, fan and compressor applications. 

While general-purpose motors are appropriate for use in day-to-day applications in standard environmental conditions, the Severe Duty motors with their rugged cast-iron housing fulfill the more demanding requirements found in the paper and printing industry, as well as the chemicals and petrochemicals industry.

Siemens Boosts Safety through Gas Analyser Technology

Siemens UK & Ireland has announced a series of product developments across its gas and oxygen analyser portfolio designed to optimise safety and efficiency, whilst enabling customers to meet stringent industry regulations.

First comes the launch of the Siprocess UV600, a gas analyser which uses ultraviolet technology for the measurement of low concentrations of notoriously difficult to measure components, such as NO, NO2, SO2 and H2S.

Suitable for a range of applications in chemical and industrial processes, the Siprocess UV600 is an ideal tool for monitoring gas turbine emissions and forms part of Siemens’ emissions monitoring package, which is designed to help end users meet strict regulations, such as Annex V of the Industrial Emissions Directive. The Siprocess UV600, which is MCERTS approved, uses ultraviolet absorption techniques to ensure high speciation of measured components free from cross interferences.

The compact solution occupies a 4U panel height enclosure, so plants can enhance efficiency by avoiding the use of maintenance-heavy catalytic converters or ozone generators for total NOx measurements.

Meanwhile, Siemens’ Ultramat 6 multi-gas analyser has gained German Lloyd certification, meeting the requirements of MPEC 184(59) and MARPOL Annex VI for the ship board emissions monitoring duty.

As a quality tested and approved solution for the continuous monitoring of SO2 and CO2 emissions, Ultramat 6 offers greater assurance to end users when it comes to meeting stringent requirements - such as the introduction of Emission Control Areas - to reduce emissions of sulphur dioxide from marine fuel combustion.

The Ultramat 6 can be supplied directly to end-users or made available to systems integrators for inclusion in complete gas cleaning, monitoring and reporting packages.

Finally, Siemens’ Oxymat 6/61 series has now been released with a Safety Integrity Level (SIL) 2 rating. The oxygen analyser solution for standard applications incorporates a paramagnetic alternating pressure method and microflow sensor technology to provide a high degree of reliability and accuracy when measuring oxygen in gases.

The Oxymat series can be used in applications with up to 100% oxygen with a suppressed zero and Siemens is able to offer customers an additional ‘cleaned for oxygen service’, ensuring total process safety.

The solution’s SIL 2 classification makes it easier for plant operators to comply with statutory requirements regarding the verification of risk reduction.

Shawn Pullman, Product Manager – CGA & Laser, at Siemens UK & Ireland comments: “The developments and new certifications across our key gas and oxygen analyser ranges means we’re able to offer customers greater assurance that by using our products and services, they are equipped to meet industry regulations and challenges now, and in the future. We’re committed to building on our solutions and product certifications to continue to deliver the very best in process safety and efficiency for customers.”

The world’s smallest resistances.

Scientists investigate voltage drop with sub-nanometer resolution.

Scientists from the Universities of Göttingen and Erlangen have made an important step towards a deeper understanding of smallest resistances. Using a scanning tunnelling microscope, the researchers succeeded in resolving the spatial extent of a voltage drop with sub-nanometer resolution for the first time. Their results were published in Nature Communications.

The physicists investigated the relationship between the voltage drop and resistance on the atomic scale. As their sample system they used graphene, a single layer of hexagonally oriented carbon atoms.

In their experiments, a current-carrying layer of graphene showed the expected linear voltage drop in defect-free regions of the sample. This is in contrast to the behaviour at local defects, for example the transition between layers: These transitions form barriers where the electrons are reflected, which leads to an abrupt voltage drop.

“Our findings show that the voltage drop is much greater in size than the actual defect,” explains doctoral candidate Philip Willke from Göttingen University’s IV. Physical Institute.

“Furthermore, we observed that the voltage drop is located almost completely in the bilayer. This problem can be compared to a highway that changes from two lanes to only one. The lane change, or in this case the change from one layer of graphene to the other, is extremely hard for the electrons.”

“Our results demonstrate that it is possible to characterise electron transport in non-equilibrium on the atomic scale and to distinguish between different scattering contributions,” adds Dr. Martin Wenderoth, head of the group.

“So far, this was only possible by theoretical calculations. Our findings will help to prove current theories and to establish a deeper understanding of electron transport itself.”

Materials sciences - an interdisciplinary research field.

Materials sciences - an interdisciplinary research field.

Materials sciences involves the research, development, characterization, manufacture and processing of materials.

Materials sciences- the basis

As an interdisciplinary field, materials sciences encompasseschemistry, physics, mineralogyand many other areas of science. As a result, it is also tied closely to copper, iron and steel.

The transition from natural materials such as stone, wood, ivory or leather to the targeted production of materials such as copper, steel or iron.

Copper, steel and iron were produced as early as the Neolithic, roughly around 4,300 B.C. Copper and iron were produced as far back as the New Stone Age, roughly 4,300 B.C. This was then followed by the transition to the Bronze Age. It wasn't until the Iron Age that apart from iron, steel and copper, aluminum was also produced using the Hall-Héroult process. For a long time, materials sciences was interested almost exclusively in metals such as iron, copper and steel. However, this has changed with the rediscovery of concrete. While the first, mass-produced plastic materials eventually attracted the interest of the broad public, materials sciences continues to carry out research into iron, copper and steel.

The first metals and the ancient times

Copper, steel and iron were the first metals that mankind became familiar with as it evolved. Copper is very easy to process. As a result, copper was already being used 10,000 years ago by the oldest known cultures 10,000. The era of large-scale copper use (between 3,000 and 5,000 B.C.) is referred to as the Copper Age. The devotees of alchemy associate copper with Venus, the symbol of femininity. The first mirrors were even made from copper. The Roman Empire was the largest producer of copper prior to the Industrial Age. Copper remains an extremely popular material.

Steel - stable and dependable

Mankind has acquired long years of practical experience with steel. Steel is a preferred material in engineering because of its durability, excellent corrosion properties and suitability for welding. It is significantly more stable than copper. The European steel registry lists more than 2,300 types of steel. Coal and steel served as the pillars of heavy industry over a long period of time and were thus the foundations of political power. Steel is defined as an iron-carbon alloy with less than 2.06 percent carbon content. Steel, or iron, has a density of 7.85-7.87 g/cm3. Steel melts at a temperature that can be as high as 1,536°C and therefore withstands much higher temperatures than copper.Steel was first produced around 1,000 B.C., much later than copper. In an ecological sense, steel is a sustainable material because it can be continuously reused with minimal quality loss.

Iron - from decoration to general utility

The use of iron was first recorded around 4,000 B.C. in Egypt. It was a solid iron used for decorations and for making spear tips. It was more suitable for these purposes than steel or copper. Smelted iron appeared later in Mesopotamia and Egypt, but it was only intended for ceremonial purposes. Perhaps iron came about as a byproduct of bronze production. After the Hethiter developed a method to produce iron, cultures became increasingly reliant on iron between 1,600 and 1,200 B.C. Iron is thought to be a major element of the earth's core, along with nickel. Iron is produced by reducing iron ore through a chemical reaction with carbon. In contrast to steel or copper, iron is produced in blast furnaces.

New materials discovered to detect neutrons emitted by radioactive materials.

Scientist Christopher Lavelle of the Johns Hopkins University Applied Physics Laboratory, together with a team of researchers from the University of Maryland and the National Institute of Standards and Technology, has successfully shown that boron-coated vitreous carbon foam can be used in the detection of neutrons emitted by radioactive materials -- of critical importance to homeland security. Lavelle is lead author of the paper "Demonstration of Neutron Detection Utilizing Open Cell Foam and Noble Gas Scintillation" released today in the journal Applied Physics Letters.

Detecting neutrons is key to counterterrorism activities, such as screening cargo containers, as well as other vital applications in nuclear power instrumentation, workplace safety and industry. The demand for detectors has risen dramatically over the past decade while at the same time the usual detection material, helium-3, has become harder to obtain. An advantage of the approach outlined in the paper is that boron is abundant and relatively low cost compared to helium-3. The use of a coated foam, in particular, disperses the boron evenly throughout the detector volume, increasing efficiency by filling in otherwise empty space.

Lavelle and his colleagues' work builds on a series of experiments conducted with scientists at NIST and the University of Maryland that had demonstrated that a process called noble gas scintillation can be controlled and characterized precisely enough to detect the neutrons emitted by radioactive materials. Scintillation refers to a process where energetic particles produce flashes of light when passing through certain materials, in this case xenon gas. Sensitive light detectors record the rate at which these light flashes occur to measure the presence and intensity of neutrons in the environment.

In a follow-on experiment, the research team obtained samples of "carbon foam" coated with boron carbide and placed them in xenon gas. The boron-10 isotope in the coating readily absorbs neutrons. Following neutron absorption, energetic particles are released into the gas and create flashes of light. In this experiment, researchers determined that neutrons captured deep within the coated foam produce large enough flashes to be detected by light detectors outside the foam. Previously, there had been some doubt as to whether the light flashes would actually escape foam, or if the foam would completely shadow them from the light detector.

The next steps in the series of experiments include investigating other unique detector geometries, such as multiple layers of boron-coated thin films, the use of optically transparent neutron absorbers, and finalizing a design for a potential prototype detector.

The future of electronics -- now in 2-D

Work could ultimately lead to electrical conductors that are 100 percent efficient.

The future of electronics could lie in a material from its past, as researchers from The Ohio State University work to turn germanium--the material of 1940s transistors--into a potential replacement for silicon.

At the American Association for the Advancement of Science meeting, assistant professor of chemistry Joshua Goldberger reported progress in developing a form of germanium called germanane.

In 2013, Goldberger's lab at Ohio State became the first to succeed at creating one-atom-thick sheet of germanane--a sheet so thin, it can be thought of as two-dimensional. Since then, he and his team have been tinkering with the atomic bonds across the top and bottom of the sheet, and creating hybrid versions of the material that incorporate other atoms such as tin.

The goal is to make a material that not only transmits electrons 10 times faster than silicon, but is also better at absorbing and emitting light--a key feature for the advancement of efficient LEDs and lasers.

"We've found that by tuning the nature of these bonds, we can tune the electronic structure of the material. We can increase or decrease the energy it absorbs," Goldberger said. "So potentially we could make a material that traverses the entire electromagnetic spectrum, or absorbs different colors, depending on those bonds."

As they create the various forms of germanane, the researchers are trying to exploit traditional silicon manufacturing methods as much as possible, to make any advancements easily adoptable by industry.

Aside from these traditional semiconductor applications, there have been numerous predictions that a tin version of the material could conduct electricity with 100 percent efficiency at room temperature. The heavier tin atom allows the material to become a 2D "topological insulator," which conducts electricity only at its edges., Goldberger explained. Such a material is predicted to occur only with specific bonds across the top and bottom surface, such as a hydroxide bond.

Goldberger's lab has verified that this theoretical material can be chemically stable. His lab has created germanane with up to 9 percent tin atoms incorporated, and shown that tin atoms have strong preference to bond to hydroxide above and below the sheet. His group is currently developing routes towards preparing the pure tin 2D derivatives.

Improved fire detection with new ultra-sensitive, ultraviolet lightsensor.

Researchers at the University of Surrey's Advanced Technology Institute manipulated zinc oxide, producing nanowires from this readily available material to create a ultra-violet light detector which is 10,000 times more sensitive to UV light than a traditional zinc oxide detector.

Currently, photoelectric smoke sensors detect larger smoke particles found in dense smoke, but are not as sensitive to small particles of smoke from rapidly burning fires.

Researchers believe that this new material could increase sensitivity and allow the sensor to detect distinct particles emitted at the early stages of fires, paving the way for specialist sensors that can be deployed in a number of applications.

"UV light detectors made from zinc oxide have been used widely for some time but we have taken the material a step further to massively increase its performance. Essentially, we transformed zinc oxide from a flat film to a structure with bristle-like nanowires, increasing surface area and therefore increasing sensitivity and reaction speed," said Professor Ravi Silva, co-author of the study and head of the Advanced Technology Institute.

The team predict that the applications for this material could be far reaching. From fire and gas detection to air pollution monitoring, they believe the sensor could also be incorporated into personal electronic devices, such as phones and tablets, to increase speed, with a response time 1000 times faster than traditional zinc oxide detectors.

"This is a great example of a bespoke, designer nanomaterial that is adaptable to personal needs, yet still affordable. Due to the way in which this material is manufactured, it is ideally suited for use in future flexible electronics, a hugely exciting area," added Professor Silva.

About the Advanced Technology Institute at the University of Surrey:

The Advanced Technology Institute (ATI) at the University of Surrey is an established, multi-disciplinary centre of excellence in Nanotechnology and Photonics. It acts as a "technology hotel" encouraging interaction between researchers in advanced functional materials and the devices that these enable. There is especial interest in the application of technologies to the grand challenges in energy, clean water and healthcare, enabled by nanoscale design of electronics and photonic devices.

The ATI interacts with other centres of excellence at Surrey, who bring expertise, inter alia, in structural materials, telecommunications and space. It engages with industry at all levels from SMEs to multi-nationals, and in helping to establish standards with our principal collaborator, the National Physical Laboratory. The ATI was delighted to recently welcome Dr Chris Mills from Tata's research laboratories who joins us for a two year secondment to build on collaborations developing applications for graphene.

Graphene, the wonder material, goes textile.

Surface coating sets new standards for personal protective equipment (PPE).

What does a graphite or lead pencil have to do with a spectacular discovery in the world of materials research? Graphene is a single layer of carbon just one atom thick, in the form of a honeycomb lattice made up of hexagons. (see Text box 1)

This layer, just a few nanometres thick, can only be seen under a scanning tunnelling microscope and holds within it the technology of tomorrow. The material is multifunctional: ultra-thin and therefore transparent, an extremely efficient conductor of electricity and heat, with higher tensile strength than steel, yet flexible and abrasion-resistant and impermeable to gases.

These outstanding properties of graphene mean that it has many potential uses in industry. While research is making rapid progress especially in the field of conductivity, the use of graphene in the textile sector has so far been somewhat overlooked.

This is where a research project run by scientists at the Hohenstein Institut für Textilinnovation gGmbH in Bönnigheim, in partnership with the companies IoLiTec Ionic Liquids Technologies GmbH from Heilbronn and FUCHSHUBER TECHNO-TEX-GmbH from Lichtenstein, and Belgian project partners Centexbel and Soieries Elite, comes in. The team led by Project Manager Dr. Roshan Paul is working within the EU research funding programme "M-era.Net" on the German sub-project called "GRAFAT – Using graphene for the surface modification of textiles in heat protective clothing" (sponsorship ID 03X0157A).

"Over the next three years, the consortium will be investigating to what extent the surface of textiles can be changed using graphene modifications (see Text box 2), in particular with a view to later applying the process to heat protective clothing. Graphene has all kinds of positive properties which would revolutionise this sector. This research makes us world leaders in using graphene modification on textile surfaces," says Dr. Paul. The transformation of the various graphene modifications into stable aqueous dispersions is being carried out by Iolitec.

The aim of the Hohenstein research team is to develop stable techniques for applying aqueous graphene dispersions, so that they can be used as a permanent coating on different textile surfaces. A range of different graphene modifications (e.g. graphene oxide, "multi-layer graphene") are being considered, since they each have different properties.

The newly developed surface modifications for the various textiles will then be analysed for their suitability for heat protective equipment. In the research work, the company FUCHSHUBER TECHNO TEX has the task of converting the application formula that has been developed to an industrial scale and ensuring that the treated textiles can be cleaned and processed. The aim is to produce a demonstrator model.

Using graphene to modify the surface can significantly improve the flame-retardant properties of a textile. Graphene can act as a physical barrier, effectively preventing the penetration of heat and gases. At the same time, graphene also has the potential to prevent the thermal decomposition of the textile. Another benefit of graphene is its resistance to abrasion and rupture, about 200 times higher than that of steel. These qualities also make graphene extremely interesting for applications in the field of personal protective equipment.

Normally, the functionalisation of textiles for PPE requires a multi-stage process. This may no longer be necessary if graphene can be applied in a single-stage process. The material used for PPE could then be thinner and therefore lighter. This in turn increases the wearer's mobility.

"If their functionality can be successfully proven, textiles with graphene-modified surfaces could find many uses in the PPE sector, especially in heat protective clothing," says Dr. Paul. This would open up a new market segment for the use of graphene, further enhancing the economic success of innovative companies and the industry in general.

Text box 1:

Graphene is a layer of pure carbon, just one atom thick. A distinction is made between single-layer and multi-layer graphene and graphene with more than 10 layers, which is called graphite (pencil lead). Even though the structure is the same, the different numbers of layers result in different properties. 

A graphene layer is about 0.3 nanometres thick, just one hundred-thousandth of the thickness of a human hair. Each carbon atom in the layer is bonded to three more carbon atoms, creating a two-dimensional honeycomb-like layered structure.

Text box 2:

Graphene and oxygen can be converted into graphene oxide which can contain different amounts of bound oxygen. By linking or functionalising it with other molecules or atoms, different chemical properties can be produced in the material.

Black Phosphorus Is New ‘Wonder Material’ for Improving OpticalCommunication.

Phosphorus, a highly reactive element commonly found in match heads, tracer bullets, and fertilizers, can be turned into a stable crystalline form known as black phosphorus. In a new study, researchers from the University of Minnesota used an ultrathin black phosphorus film—only 20 layers of atoms—to demonstrate high-speed data communication on nanoscale optical circuits.

The devices showed vast improvement in efficiency over comparable devices using the earlier “wonder material” graphene.

The work by University of Minnesota Department of Electrical and Computer Engineering Professors Mo Li and Steven Koester and graduate students Nathan Youngblood and Che Chen was published today in Nature Photonics—a leading journal in the field of optics and photonics.

As consumers demand electronic devices that are faster and smaller, electronics makers cram more processor cores on a single chip, but getting all those processors to communicate with each other has been a key challenge for researchers. The goal is to find materials that will allow high-speed, on-chip communication using light.

While the existence of black phosphorus has been known for more than a century, only in the past year has its potential as a semiconductor been realized. Due to its unique properties, black phosphorus can be used to detect light very effectively, making it desirable for optical applications. For the first time, the University of Minnesota team created intricate optical circuits in silicon and then laid thin flakes of black phosphorus over these structures using facilities at the University’s Minnesota Nano Center.

“After the discovery of graphene, new two-dimensional materials continue to emerge with novel optoelectronic properties,” said Professor Li, who led the research team. “Because these materials are two-dimensional, it makes perfect sense to place them on chips with flat optical integrated circuits to allow maximal interaction with light and optimally utilize their novel properties.”

The University of Minnesota team demonstrated that the performance of the black phosphorus photodetectors even rivals that of comparable devices made of germanium—considered the gold standard in on-chip photodetection. Germanium, however, is difficult to grow on silicon optical circuits, while black phosphorus and other two-dimensional materials can be grown separately and transferred onto any material, making them much more versatile.

The team also showed that the devices could be used for real-world applications by sending high-speed optical data over fibers and recovering it using the black phosphorus photodetectors. The group demonstrated data speeds up to three billion bits per second, which is equivalent to downloading a typical HD movie in about 30 seconds.

“Even though we have already demonstrated high speed operation with our devices, we expect higher transfer rates through further optimization,” said Nathan Youngblood, the lead author of the study. “Since we are the first to demonstrate a high speed photodetector using black phosphorus, more work still needs to be done to determine the theoretical limits for a fully optimized device.”

Bridging the gap

While black phosphorus has much in common with graphene—another two-dimensional material—the materials have significant differences, the most important of which is the existence of an energy gap, often referred to as a “band gap.”

Materials with a band gap, known as “semiconductors,” are a special group of materials that only conduct electricity when the electrons in that material absorb enough energy for them to “jump” the band gap. This energy can be provided through heat, light, and other means.

While graphene has proven useful for a wide variety of applications, its main limitation is its lack of a band gap. This means that graphene always conducts a significant amount of electricity, and this “leakage” makes graphene devices inefficient. In essence, the device is “on” and leaking electricity all the time.

Black phosphorus, on the other hand, has a widely-tunable band gap that varies depending on how many layers are stacked together. This means that black phosphorus can be tuned to absorb light in the visible range but also in the infrared. This large degree of tunability makes black phosphorus a unique material that can be used for a wide range of applications—from chemical sensing to optical communication.

Additionally, black phosphorus is a so-called “direct-band” semiconductor, meaning it has the potential to efficiently convert electrical signals back into light. Combined with its high performance photodetection abilities, black phosphorus could also be used to generate light in an optical circuit, making it a one-stop solution for on-chip optical communication.

“It is really exciting to think of a single material that can be used to send and receive data optically and is not limited to a specific substrate or wavelength,” Youngblood said. “This could have huge potential for high-speed communication between CPU cores which is a bottleneck in computing industry right now.”

Fast growing potential

The past several years have seen a flurry of two-dimensional material discoveries, first with graphene, more recently with transition metal dichalcogenides (TMDs) such as molybdenum disulphide (MoS2), and now black phosphorus. All of the previous two-dimensional materials have serious trade offs, but black phosphorus provides the “best of both worlds” with a tunable band gap and high-speed capability.

“Black phosphorus is an extremely versatile material,” said Professor Steven Koester, who contributed to the project. “It makes great transistors and photodetectors, and has the potential for light emission and other novel devices, making it an ideal platform for a new type of adaptable electronics technology.”

The University of Minnesota research was funded by the Air Force Office of Scientific Research and the National Science Foundation.

Chemists develop new way to make cost-effective material for electricity storage.

University of British Columbia researchers have found a new way to make state-of-the-art materials for energy storage using a cheap lamp from the hardware store.

The researchers wanted to find a better way to make coatings that can be painted onto surfaces to conduct electricity or convert electricity into hydrogen fuels. Typically these coatings are made in more extreme conditions with expensive tools and materials.

But the researchers developed a technique that allows them to use a consumer grade heat lamp to get the same results. Once the solution was painted onto a surface and heated up, it transformed into a catalytic coating.

These coatings can be used in a range of technologies, such as flexible electronic devices or to convert electricity into hydrogen fuels. The discovery, published today in the new open access These coatings can be used in a range of technologies, such as flexible electronic devices or to convert electricity into hydrogen fuels. The discovery, published today in the new open access journal Science Advances, could have implications for consumer electronics and clean energy technologies.

"Solar farms and wind turbines don't provide a constant supply of energy," says study co-author Curtis Berlinguette, an associate professor in UBC's Departments of Chemistry and Chemical and Biological Engineering. "Storing electrical energy produced during times of low demand as hydrogen fuels enables that electricity to be used later during peaks of higher demand. The catalyst coatings we can now produce more easily could help make this process cheaper and more efficient."

The researcher's new technique may also help reduce the fabrication costs of making catalyst-coated electrodes in commercial applications, such as electrolyzers.

"The technique is scalable and amenable to large-scale manufacturing," says Danielle Salvatore, a chemical engineering graduate student and the paper's lead author.

"We can create these materials on any surface without an expensive pre University of British Columbia researchers have found a new way to make state-of-the-art materials for energy storage using a cheap lamp from the hardware store.

The researchers wanted to find a better way to make coatings that can be painted onto surfaces to conduct electricity or convert electricity into hydrogen fuels. Typically these coatings are made in more extreme conditions with expensive tools and materials.

But the researchers developed a technique that allows them to use a consumer grade heat lamp to get the same results. Once the solution was painted onto a surface and heated up, it transformed into a catalytic coating.

These coatings can be used in a range of technologies, such as flexible electronic devices or to convert electricity into hydrogen fuels. The discovery, published today in the new open access These coatings can be used in a range of technologies, such as flexible electronic devices or to convert electricity into hydrogen fuels. The discovery, published today in the new open access journal Science Advances, could have implications for consumer electronics and clean energy technologies.

"Solar farms and wind turbines don't provide a constant supply of energy," says study co-author Curtis Berlinguette, an associate professor in UBC's Departments of Chemistry and Chemical and Biological Engineering. "Storing electrical energy produced during times of low demand as hydrogen fuels enables that electricity to be used later during peaks of higher demand. The catalyst coatings we can now produce more easily could help make this process cheaper and more efficient."

The researcher's new technique may also help reduce the fabrication costs of making catalyst-coated electrodes in commercial applications, such as electrolyzers.

"The technique is scalable and amenable to large-scale manufacturing," says Danielle Salvatore, a chemical engineering graduate student and the paper's lead author.

"We can create these materials on any surface without an expensive precursor," says Berlinguette, explaining that these findings build on earlier work of using more expensive UV light to create catalytic films .

cursor," says Berlinguette, explaining that these findings build on earlier work of using more expensive UV light to create catalytic films .

The PAL-V One, A Flying Car Worth Driving.

The PAL-V One, A Flying Car Worth Driving

The Dutch-built PAL-V One may be a realistic approach to the dream of the flying car.

The Terrafugia Transition flying car is capturing headlines after a public showing at the New York Auto Show and as it edges nearer to a limited FAA certification. However, if we're realistic about the plane-car as a consumer product, it's very unlikely to be a commercial success. PopMech has written at length about this recently, but to sum up: First, the Transition is awkward. No matter how revolutionary a car may be, it's hard to get buyers to swallow a $279,000 price tag if the thing is ugly. And if we base everything on published specs, the Terrafugia isn't very good as a car or as a plane. it's a compromise to utility and performance at everything it does—the Amphicar of the air. A product has to be good for people to want it.

And this is where I personally think the Dutch-built and recently tested PAL-V One might be a much more realistic approach to the dream of the flying car. The three-wheeled, two-passenger car has stowable, manual-folding rotors up top and an auto-folding propeller at the rear. The reasons it's a better concept? First of all, it looks cool, or at least as cool as possible when toting along flight gear. Second, it should be able to handle quite well since it uses lightweight construction as well as a leaning suspension system borrowed from the Carver One.

The third reason is safety. Powered heavier-than-air flight is dangerous. It's really the biggest barrier to putting millions of motorists in the air (and all our road rage would cause catastrophes in the skies). But there is another thing to consider; Fixed-wing flight like the Terrafugia Transition uses is only slightly safer than rotary wing flight, like a helicopter. Loss of power in either one of these situations is a pretty serious emergency.

The PAL-V One, however, uses an alternative: gyrorotor flight. In this style of aircraft, an unpowered rotary wing rides above the fuselage at a controlled angle while a pushing propeller drives the vehicle forward. As it accelerates, the rotary wing picks up angluar velocity and eventually develops lift the same way a helicopter does. Because this wing is unpowered and dependent only upon forward motion for rotation and lift, loss of power isn't as dangerous. These craft can safely land completely without power.

Danger does lurk, though, because autogyros are subject to something called pilot induced oscillation, a situation in which an inexperienced pilot exceeds the performance limits of the craft and causes an unrecoverable stall. With modern electronic nannies, however, this problem should never surface.

There are other appealing elements of the PAL-V One. A takeoff runway of just 540 feet and a landing requirment of 100 feet mean the craft can take off and land almost anywhere that's flat. A single engine keeps weight, cost, and complexity to a minimum. Top speeds of 112 mph on land and in air mean it'll keep up with traffic in either situation.

There are plenty of pitfalls ahead of the PAL-V One though. Concepts like this always look great on paper, but getting down to the details of funding, certification, and production seem to be the hardest part of the flying car fantasy. We'll be watching closely.

Carbon Fiber Grids Replace Steel as Innovative Concrete Reinforcement.

Facade panels with carbon fiber 3D grid reinforcement on a new factory building for Alphabeton AG in Büron (Switzerland).

The corrosion resistance of carbon fibers permits thin concrete facades

Wiesbaden, August 16, 2013. The three-dimensional carbon fiber reinforcement newly developed by SGL Group - The Carbon Company and V. FRAAS Solutions in Textile GmbH has passed the practical test. Using these three-dimensional carbon fiber grids as reinforcement, it was possible to produce concrete facade panels only 26 mm thick. A steel-reinforced facade panel of similar size has a minimum thickness of 100 mm.

The facade panels were installed on a new factory building for Alphabeton AG in Büron (Switzerland), in which precast concrete elements will be produced. Alphabeton AG are specialists in concrete products manufactured from high-performance and ultrahigh-performance concrete (UHPC) and make full use of innovative technologies.

Hans-Peter Felder, who is responsible for research & development at Alphabeton, said: “We were looking for a solution that would enable us to produce thin concrete facade panels in large dimensions. The new 3D carbon fiber grids impressed us with their light weight and corrosion resistance and were easy and convenient to process”.

Peter Weber, Vice President Sales & Marketing, Business Unit Carbon Fibers & Composite Materials of SGL Group, said: “In this application, we particularly exploit the corrosion resistance of our carbon fibers. Thanks to this advantageous property, we can dispense with the thick concrete covering obligatory with steel-reinforced concrete and produce thin concrete elements”.

V. FRAAS Solutions in Textile GmbH has developed a production plant in which the new 3D textile reinforcement based on SIGRAFIL® C carbon fibers from SGL Group can be manufactured in large dimensions for the first time.

These structural reinforcing materials based on carbon fibers are also being used in the repair and renovation sector. As a result of the special properties of carbon fibers, such as high strength and stiffness combined with light weight, bridges and buildings can be permanently renovated.

Technical Details of the Façade Panels Used

• Design: ventilated curtain wall covering a total area of 450 m² 

• Approx. 350 facade panels 

• Facade panel dimensions: 865 x 1620 mm, thickness: 26 mm 

• Structure of the SIGRATEX® 3D carbon fiber reinforcement: two layers of carbon fiber nets spaced 12 mm apart, connected by compression-resistant pile threads.

Strongest known natural material – spider silk or limpet teeth?

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   A limpet is an aquatic snail with a shell broadly conical in shape. "Limpet" informally refers to any gastropod whose shell has no obvious coiling as in familiar garden snails or in winkles.

Spider silk may lose its claim as the strongest known natural material after researchers found that limpet teeth have more mettle.

Spider silk is hailed by scientists for its strength and structure, but researchers in Britain have discovered that limpets — snail-like sea creatures with conical shells — have teeth with structures so strong they could be copied and used in making cars, boats and planes.

“Until now we thought that spider silk was the strongest biological material because of its super-strength and potential applications in everything from bullet-proof vests to computer electronics,” said Asa Barber, a professor at Portsmouth University’s school of engineering, who led the study.

“But now we have discovered that limpet teeth exhibit a strength that is potentially higher.”

Barber’s team examined the detailed mechanical behaviour of teeth from limpets with atomic force microscopy, a method used to pull apart materials all the way down to the level of the atom. They found the teeth contain a hard mineral known as goethite, which forms in the limpet as it grows.

The research was published on Wednesday in the Royal Society’s scientific journal, Interface.

“Limpets need high-strength teeth to rasp over rock surfaces and remove algae for feeding when the tide is in,” Barber said. “We discovered that the fibres of goethite are just the right size to make up a resilient composite structure.”

The fibrous structures found in limpet teeth could in future be copied by materials scientists and used in high-performance engineering applications such as Formula 1 racing cars, the hulls of boats and the bodies of aircraft, Barber said.

First solar powered plane in the world takes off from UAE

Two pilots attempting the first flight around the world in a solar-powered plane began the maiden leg of their voyage on Monday, the mission’s official website said.

Solar Impulse 2 took off from Abu Dhabi in the United Arab Emirates en route to the Omani capital Muscat at the start of a five-month journey of 35,000 km (22,000 miles) organized to focus the world’s attention on sustainable energy.

“Solar Impulse wants to mobilize public enthusiasm in favor of technologies that will allow decreased dependence on fossil fuels, and induce positive emotions about renewable energies,” said the mission website, which maps out the plane’s location and broadcasts audio from the cockpit in real time.

The plane is only as heavy a family car (2,300 kg, 5,100 pounds) and but has a wingspan as wide as the largest passenger airliner. Its journey will span approximately 25 flight days broken up into 12 legs at speeds between 50 and 100 km (30 to 60 miles) per hour.

Studies, design and construction took 12 years and a first version of the craft rolled out in 2009 broke records for heights and distances traveled by a manned solar plane.

The flight will make stopovers in India, Myanmar and China before crossing the Pacific Ocean and flying across the United States and southern Europe to arrive back in Abu Dhabi.

“Miracles can be achieved with renewables such as solar power,” Swiss pilot Bertrand Piccard, who also made the first non-stop circumnavigation of the globe in a balloon in 1999, told Reuters in January.

“We want to show we can fly day and night in an aircraft without a drop of fuel,” he said.

Companies involved in the project include Bayer AG, Solvay, ABB, Schindler, Omega and Abu Dhabi’s Masdar.

Self cleaning paint made from coated titanium dioxidenanoparticles.

British and Chinese scientists say they have developed a new paint that can be applied to clothes, paper, glass and steel to make resilient surfaces that can self-clean even after being scratched or scuffed.

In research published in the journal Science on Thursday, the scientists said the paint, made from coated titanium dioxide nanoparticles, is extremely repellent to water but, unlike other waterproof coatings, continues to work even when damaged or exposed to oil.

Because it is so hard-wearing, it could be used for a wide range of applications, from clothing to cars.

“The biggest challenge for self-cleaning surfaces is finding a way to make them tough enough to withstand everyday damage,” said Claire Carmalt, a professor of inorganic chemistry at University College London, who co-led the research.

“The surfaces tend to be mechanically weak and so rub off easily. But by pairing our paint with different adhesives, we’ve shown it is possible to make a robust self-cleaning surface.”

In their experiments, Carmalt’s team used different coating methods to create repellent surfaces, depending on the material.

To coat glass and steel, they used a spray-gun, for cotton wool they used dip-coating, and for paper a syringe.

“Being waterproof allows materials to self-clean, as water forms marble-shaped droplets that roll over the surface, acting like miniature vacuum cleaners picking up dirt, viruses and bacteria along the way,” said Yao Lu of UCL’s chemistry department, who co-led the study.

“For this to happen the surface must be rough and waxy, so we set out to create these conditions on hard and soft surfaces by designing our own paint and combining it with different adhesives.”

The team’s results showed that in all cases, the materials became waterproof and self-cleaning, with water droplets of different sizes bouncing off them and taking dirt with them. This continued even after the materials were scratched with a knife or scuffed with sandpaper.

Urine can generate electricity to light camps in disaster zone.

A toilet, conveniently situated near the Student Union Bar at the University of the West of England (UWE Bristol), is proving that urine can generate electricity.

The prototype urinal is the result of a partnership between researchers at UWE Bristol and Oxfam. It is hoped the pee-power technology will light cubicles in refugee camps, which are often dark and dangerous places particularly for women.

Students and staff are being asked to use the urinal to donate pee to fuel microbial fuel cell (MFC) stacks that generate electricity to power indoor lighting.

The research team is led by Professor Ioannis Ieropoulos, Director of the Bristol BioEnergy Centre located in the Bristol Robotics Laboratory at UWE Bristol.

Professor Ieropoulos says, "We have already proved that this way of generating electricity works. Work by the Bristol BioEnergy Centre hit the headlines in 2013 when the team demonstrated that electricity generated by microbial fuel cell stacks could power a mobile phone. This exciting project with Oxfam could have a huge impact in refugee camps.

"The microbial fuel cells work by employing live microbes which feed on urine (fuel) for their own growth and maintenance. The MFC is in effect a system which taps a portion of that biochemical energy used for microbial growth, and converts that directly into electricity -- what we are calling urine-tricity or pee power. This technology is about as green as it gets, as we do not need to utilise fossil fuels and we are effectively using a waste product that will be in plentiful supply."

The urinal on the University campus resembles toilets used in refugee camps by Oxfam to make the trial as realistic as possible. The technology that converts the urine into power sits underneath the urinal and can be viewed through a clear screen.

Andy Bastable, Head of Water and Sanitation at Oxfam, says, "Oxfam is an expert at providing sanitation in disaster zones, and it is always a challenge to light inaccessible areas far from a power supply. This technology is a huge step forward. Living in a refugee camp is hard enough without the added threat of being assaulted in dark places at night. The potential of this invention is huge."

Both Professor Ieropoulos and Andy Bastable agree it is the cheap, sustainable aspect of this technology, which relies on the abundant, free supply of urine that makes it so practical for aid agencies to use in the field.

Professor Ieropoulos says "One microbial fuel cell costs about £1 to make, and we think that a small unit like the demo we have mocked up for this experiment could cost as little as £600 to set up, which is a significant bonus as this technology is in theory everlasting."

It certainly brings new meaning to the idea of spending a penny in the fight against poverty.

Nano-medicine drug combinations achieved maximum efficiency in cancer therapy.

Source: University of California - Los Angeles

Summary: Designing optimized combination therapies for cancer is remarkably difficult due to the infinite possible drug dose ratios and variable patient-specific response to treatment. In a landmark advance for personalized medicine, bioengineers have developed a novel technology that, for the first time, overcomes these challenges. By assessing phenotype, or physical biological traits as they respond to chemotherapy to drive a powerful analytics platform, the most effective and safe drug combinations possible can be systematically designed.

In greater than 90 percent of cases in which treatment for metastatic cancer fails, the reason is that the cancer is resistant to the drugs being used. To treat drug-resistant tumors, doctors typically use multiple drugs simultaneously, a practice called combination therapy. And one of their greatest challenges is determining which ratio and combination -- from the large number of medications available -- is best for each individual patient.

Dr. Dean Ho, a professor of oral biology and medicine at the UCLA School of Dentistry, and Dr. Chih-Ming Ho, a professor of mechanical engineering at the UCLA Henry Samueli School of Engineering and Applied Science, have developed a revolutionary approach that brings together traditional drugs and nanotechnology-enhanced medications to create safer and more effective treatments. Their results are published in the peer-reviewed journal ACS Nano.

Chih-Ming Ho, the paper's co-corresponding author, and his team have developed a powerful new tool to address drug resistance and dosing challenges in cancer patients. The tool, Feedback System Control.II, or FSC.II, considers drug efficacy tests and analyzes the physical traits of cells and other biological systems to create personalized "maps" that show the most effective and safest drug-dose combinations.

Currently, doctors use people's genetic information to identify the best possible combination therapies, which can make treatment difficult or impossible when the genes in the cancer cells mutate. The new technique does not rely on genetic information, which makes it possible to quickly modify treatments when mutations arise: the drug that no longer functions can be replaced, and FSC.II can immediately recommend a new combination.

"Drug combinations are conventionally designed using dose escalation," said Dean Ho, a co-corresponding author of the study and the co-director of the Jane and Jerry Weintraub Center for Reconstructive Biotechnology at the School of Dentistry. "Until now, there hasn't been a systematic way to even know where the optimal drug combination could be found, and the possible drug-dose combinations are nearly infinite. FSC.II circumvents all of these issues and identifies the best treatment strategy."

The researchers demonstrated that combinations identified by FSC.II could treat multiple lines of breast cancer that had varying levels of drug resistance. They evaluated the commonly used cancer drugs doxorubicin, mitoxantrone, bleomycin and paclitaxel, all of which can be rendered ineffective when cancer cells eject them before they have had a chance to function.

The researchers also studied the use of nanodiamonds to make combination treatments even more effective. Nanodiamonds -- byproducts of conventional mining and refining operations -- have versatile characteristics that allow drugs to be tightly bound to their surface, making it much harder for cancer cells to eliminate them and allowing toxic drugs to be administered over a longer period of time.

The use of nanodiamonds to treat cancer was pioneered by Dean Ho, a professor of bioengineering and member of the UCLA Jonsson Comprehensive Cancer Center and the California NanoSystems Institute.

"This study has the capacity to turn drug development, nano or non-nano, upside-down," he said. "Even though FSC.II now enables us to rapidly identify optimized drug combinations, it's not just about the speed of discovering new combinations. It's the systematic way that we can control and optimize different therapeutic outcomes to design the most effective medicines possible."

The study found that FSC.II-optimized drug combinations that used nanodiamonds were safer and more effective than optimized drug-only combinations. Optimized nanodrug combinations also outperformed randomly designed nanodrug combinations.

"This optimized nanodrug combination approach can be used for virtually every type of disease model and is certainly not limited to cancer," said Chih-Ming Ho, who also holds UCLA's Ben Rich Lockheed Martin Advanced Aerospace Tech Endowed Chair. "Additionally, this study shows that we can design optimized combinations for virtually every type of drug and any type of nanotherapy."

Mechanical engineers develop an ‘intelligent co-pilot’ for cars.

 Semiautonomous system takes the wheel to keep drivers safe.

Barrels and cones dot an open field in Saline, Mich., forming an obstacle course for a modified vehicle. A driver remotely steers the vehicle through the course from a nearby location as a researcher looks on. Occasionally, the researcher instructs the driver to keep the wheel straight — a trajectory that appears to put the vehicle on a collision course with a barrel. Despite the driver’s actions, the vehicle steers itself around the obstacle, transitioning control back to the driver once the danger has passed.
The key to the maneuver is a new semiautonomous safety system developed by Sterling Anderson, a PhD student in MIT’s Department of Mechanical Engineering, and Karl Iagnemma, a principal research scientist in MIT’s Robotic Mobility Group.
The system uses an onboard camera and laser rangefinder to identify hazards in a vehicle’s environment. The team devised an algorithm to analyze the data and identify safe zones — avoiding, for example, barrels in a field, or other cars on a roadway. The system allows a driver to control the vehicle, only taking the wheel when the driver is about to exit a safe zone.
Anderson, who has been testing the system in Michigan since last September, describes it as an “intelligent co-pilot” that monitors a driver’s performance and makes behind-the-scenes adjustments to keep the vehicle from colliding with obstacles, or within a safe region of the environment, such as a lane or open area.
“The real innovation is enabling the car to share [control] with you,” Anderson says. “If you want to drive, it’ll just … make sure you don’t hit anything.”
The group presented details of the safety system recently at the Intelligent Vehicles Symposium in Spain.
Off the beaten path
Robotics research has focused in recent years on developing systems — from cars to medical equipment to industrial machinery — that can be controlled by either robots or humans. For the most part, such systems operate along preprogrammed paths.
As an example, Anderson points to the technology behind self-parking cars. To parallel park, a driver engages the technology by flipping a switch and taking his hands off the wheel. The car then parks itself, following a preplanned path based on the distance between neighboring cars.
While a planned path may work well in a parking situation, Anderson says when it comes to driving, one or even multiple paths is far too limiting.
“The problem is, humans don’t think that way,” Anderson says. “When you and I drive, [we don’t] choose just one path and obsessively follow it. Typically you and I see a lane or a parking lot, and we say, ‘Here is the field of safe travel, here’s the entire region of the roadway I can use, and I’m not going to worry about remaining on a specific line, as long as I’m safely on the roadway and I avoid collisions.’”
Anderson and Iagnemma integrated this human perspective into their robotic system. The team came up with an approach to identify safe zones, or “homotopies,” rather than specific paths of travel. Instead of mapping out individual paths along a roadway, the researchers divided a vehicle’s environment into triangles, with certain triangle edges representing an obstacle or a lane’s boundary.
The researchers devised an algorithm that “constrains” obstacle-abutting edges, allowing a driver to navigate across any triangle edge except those that are constrained. If a driver is in danger of crossing a constrained edge — for instance, if he’s fallen asleep at the wheel and is about to run into a barrier or obstacle — the system takes over, steering the car back into the safe zone.

Building trust
So far, the team has run more than 1,200 trials of the system, with few collisions; most of these occurred when glitches in the vehicle’s camera failed to identify an obstacle. For the most part, the system has successfully helped drivers avoid collisions.
Benjamin Saltsman, manager of intelligent truck vehicle technology and innovation at Eaton Corp., says the system has several advantages over fully autonomous variants such as the self-driving cars developed by Google and Ford. Such systems, he says, are loaded with expensive sensors, and require vast amounts of computation to plan out safe routes.
"The implications of [Anderson's] system is it makes it lighter in terms of sensors and computational requirements than what a fully autonomous vehicle would require," says Saltsman, who was not involved in the research. "This simplification makes it a lot less costly, and closer in terms of potential implementation."
In experiments, Anderson has also observed an interesting human response: Those who trust the system tend to perform better than those who don’t. For instance, when asked to hold the wheel straight, even in the face of a possible collision, drivers who trusted the system drove through the course more quickly and confidently than those who were wary of the system.
And what would the system feel like for someone who is unaware that it’s activated? “You would likely just think you’re a talented driver,” Anderson says. “You’d say, ‘Hey, I pulled this off,’ and you wouldn’t know that the car is changing things behind the scenes to make sure the vehicle remains safe, even if your inputs are not.”
He acknowledges that this isn’t necessarily a good thing, particularly for people just learning to drive; beginners may end up thinking they are better drivers than they actually are. Without negative feedback, these drivers can actually become less skilled and more dependent on assistance over time. On the other hand, Anderson says expert drivers may feel hemmed in by the safety system. He and Iagnemma are now exploring ways to tailor the system to various levels of driving experience.
The team is also hoping to pare down the system to identify obstacles using a single cellphone. “You could stick your cellphone on the dashboard, and it would use the camera, accelerometers and gyro to provide the feedback needed by the system,” Anderson says. “I think we’ll find better ways of doing it that will be simpler, cheaper and allow more users access to the technology.”
This research was supported by the United States Army Research Office and the Defense Advanced Research Projects Agency. The experimental platform was developed in collaboration with Quantum Signal LLC with assistance from James Walker, Steven Peters and Sisir Karumanchi.

Sensing skin' quickly detects cracks, damage in concrete structures

Date: March 08, 2015

Source: North Carolina State University

Summary: Researchers have developed new 'sensing skin' technology designed to serve as an early warning system for concrete structures, allowing authorities to respond quickly to damage in everything from nuclear facilities to bridges.

The “sensing skin” technology detects cracks in concrete (as in top image) and reports when and where the damage took place.

Researchers from North Carolina State University and the University of Eastern Finland have developed new "sensing skin" technology designed to serve as an early warning system for concrete structures, allowing authorities to respond quickly to damage in everything from nuclear facilities to bridges.

"The sensing skin could be used for a wide range of structures, but the impetus for the work was to help ensure the integrity of critical infrastructure such as nuclear waste storage facilities," says Dr. Mohammad Pour-Ghaz, an assistant professor of civil, construction and environmental engineering at NC State and co-author of a paper describing the work.

"The idea is to identify problems quickly so that they can be addressed before they become big problems and -- in the case of some critical infrastructure -- so that public safety measures can be implemented," Pour-Ghaz says.

The skin is an electrically conductive coat of paint that can be applied to new or existing structures. The paint can incorporate any number of conductive materials, such as copper, making it relatively inexpensive.

Electrodes are applied around the perimeter of a structure. The sensing skin is then painted onto the structure, over the electrodes. A computer program then runs a small current between two of the electrodes at a time, cycling through a number of possible electrode combinations.

Every time the current runs between two electrodes, a computer monitors and records the electrical potential at all of the electrodes on the structure. This data is then used to calculate the sensing skin's spatially distributed electrical conductivity. If the skin's conductivity decreases, that means the structure has cracked or been otherwise damaged.

The researchers have developed a suite of algorithms that allow them to both register damage and to determine where the damage has taken place.

"Determining the location of the damage based on the measured electrode potentials is a challenging mathematical problem," says Dr. Aku Seppänen, an Academy Research Fellow in the Department of Applied Physics at the University of Eastern Finland and co-author of the paper. "We had to develop new computational methods to more reliably determine where the damage is. Ultimately, I think our work represents an advance over previous algorithms in terms of accuracy."

The researchers have demonstrated the effectiveness and accuracy of the sensing skin on a small scale, using concrete beams less than a meter wide.

"Our next step is to extend this to large geometries," Pour-Ghaz says. "We want to show that this will work on real-world structures."

The paper, "Electrical impedance tomography-based sensing skin for quantitative imaging of damage in concrete," was published online June 18 in the journal Smart Materials and Structures. The research was supported in part by the Academy of Finland.