Game-changing graphene: the amazing properties of a single-atom layer of carbon

By Catherine

Written by Catherine Bolgar

 

Step aside, silicon. There’s a new substance that promises to revolutionize medicine, industry, water treatment, electronics and much more. That substance is graphene—a single-atom-thick layer of carbon, a millionth of the width of a human hair.

 

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The world’s first two-dimensional material, graphene is potentially plentiful (carbon being the sixth most abundant element in the universe) and cheap. And it possesses amazing qualities and potential uses:

It’s transparent, but conducts…

electricity and heat. Most good conductors are metals such as copper, which is opaque and quick to heat when electricity passes through. But they are prone to hot spots, which form around defects and cause electronic devices to fail. Graphene, by contrast, transfers heat efficiently. “It’s a good alternative to copper,” says Nai-Chang Yeh, professor of physics at California Institute of Technology. Indeed, electronic equipment may in future use graphene-coated copper interconnections to prevent overheating or wear and tear.

It’s light and flexible, but it is…

Hands of scientific showing a piece of graphene with hexagonal molecule.200 time stronger than steel. The carbon-to-carbon bond is very strong, says Rahul Nair, Royal Society fellow at the University of Manchester. In addition, graphene’s carbon atoms are arranged in a tight, uniform honeycomb structure, which is able to bear loads and resist tearing. A membrane of graphene could withstand strong force without breaking, says Dr. Yeh. It may someday be used in aerospace, transportation, construction and defense.

 

It’s a superlubricant

“If you take one piece of flawless graphene and put it on top of another, and slide one against the other, there’s almost no friction,” says Dr. Yeh. Coating machines parts with graphene could minimize unwanted friction, providing industry with countless applications.

It’s impermeable…

Graphene’s honeycomb structure is too tight for any molecules to squeeze through. “If you have graphene on metal, it’s perfect protection, because other molecules in the air cannot penetrate that honeycomb hole,” says Dr. Yeh. Indeed, Dr. Nair has dissolved graphene oxide in water to create a paint-like film that can protect any surface from corrosion. This graphene paint could be used by the oil and gas industry to protect equipment against saltwater, or by pharmaceutical and food packaging firms to block out oxygen and moisture, thereby extending their products’ shelf life, says Dr. Nair.

…but can also be permeable. A single-micrometer-thick film containing thousands of layers of graphene oxide has nanosize capillaries between its layers, which expand when exposed to water. However, those capillaries don’t expand when exposed to other substances. This is unusual because a water molecule is bigger than a helium or hydrogen molecule. However, water behaves differently when it’s within the confined space of a nanometer, moving rapidly through the graphene oxide nanocapillary. By contrast, salt that is dissolved in the water is blocked. One use for this, says Dr. Nair, could be water or molecular filtration.

It’s a chemical contradiction

A sheet of graphene is inert, but its edges are chemically reactive, says Dr. Yeh. A little graphene flake has a large perimeter relative to its area, allowing for more reaction. These flakes could be used to remove toxins from water.

It can be magnetic

MagnetThe zigzag-shaped edges of graphene have magnetic properties.“People imagine that you will be able to use graphene sheets as a magnet that can pick up iron at room temperature,” explains Dr. Yeh. That something all-carbon can be magnetic is “amazing,” she adds. Coupled with its electric conductivity, graphene’s magnetic properties may open up all sorts of applications in spintronics and semiconductors.

Graphene’s potential may be extraordinary, but how easy is it to create? It was first isolated in 2004 at Manchester University by Andre Geim and Konstantin Novoselov who won the 2010 physics Nobel Prize for their work. They arrived at graphene by using adhesive tape to peel off ever-thinner layers from graphite, a process subject to continual improvement. In one common method, copper is heated to 1,000 degrees Celsius, near its melting point. Methane gas, comprising carbon and hydrogen molecules, is then added, and the copper rips off the bond between the two molecules, dissolving the carbon into the copper and letting the carbon “grow” on the surface, Dr. Yeh explains. The result is a sheet of graphene.

David Boyd and Wei-Hsiang Lin, working with Dr. Yeh at Caltech, however, found that what counts most is not heat but clean copper.  Copper oxidizes quickly in air and so has a thin layer of carbon oxide on its surface. They use hydrogen plasma, which has “gas radicals that behave like erasers and clean up the surface of the copper,” Dr. Yeh explains. The process allows graphene to grow in five minutes at room temperature.

Most importantly, this method could be scaled up to produce industrial amounts of high-quality graphene—a huge step towards realizing its true potential.

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. 

For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.

 

Photos courtesy of iStock

Smart clothing moves beyond sportswear sensors

By Catherine

 

Written by Catherine Bolgar

 

Plexus-Morphing-Smart-Shirt-2
Clever clothing is moving beyondsensor-laden sportswear, adding capabilities that keep us cool, or warm, and improve our health; smart clothes might one day even make us invisible. Consider the following possibilities.

Cool under fire: Past clothing innovations, such as Kevlar, have greatly enhanced personal safety, for example, by improving bulletproof vests. But being impermeable, such vests also keep out air and trap in the wearer’s sweat. It is a problem that researchers at the Swiss Federal Laboratories for Materials Science and Technology (EMPA) have tried to solve by developing a smart protective vest with an integrated cooling system using “Coolpad” technology originally designed for medical uses.coolpadvest-2

The Coolpad consists of two breathable membranes and a thin hydrophilic textile from which the added water is evaporated for cooling. An active cooling mechanism consists of a Coolpad and a ventilation system based on a spacer fabric (a three dimensional knitted fabric) to guide the air. A tiny fan, similar to that in a computer, pumps air through the spacer fabric, which in turn guides the air through the inside of the vest, increasing evaporation and cooling the wearer, Martin Camenzind, an EMPA electronic engineer, explains. A small water reservoir creates a mist in the fabric channels and, along with the perspiration, helps cool the wearer.

The drop in temperature varies according to how the Coolpad vest is worn. Sometimes a police officer will want to display his or her bulletproof vest, other times to hide it. When worn close to the skin, over a T-shirt, it can reduce body temperature by four to six degrees Celsius, says Mr. Camenzind. “You would feel even smaller temperature changes than that,” he adds. Furthermore, the active cooling system vest weighs about one kilogram, compared with the nearly 20 kilograms of equipment—including radio, gun, flashlight and more—that police officers regularly carry.

Hot fashion: At the other end of the thermometer, nanowire clothing could keep us all warm. Stanford University researchers have developed metallic nanowire-coated fabrics that reflect body heat back to the wearer, augmented by Joule heating in which an electric current releases heat. The clothing is also breathable, so the wearer stays comfortable. One benefit of the technology lies in not having to heat a whole house for its inhabitants to stay warm.

Walk like a robot: In another remarkable development, a Bristol University research team is developing soft-robotic clothing, such as smart trousers that support wearers as they walk or climb stairs, helping to prevent falls. Wearable robotics, especially for the elderly, might be more efficient than bulky walking aids or stair lifts, and more comfortable than braces that can restrict blood circulation.

Healthy fabrics: Other smart fabrics, being developed at the University of Laval in Quebec, can monitor and wirelessly transmit a wearer’s biomedical information. Such fabrics can provide a minimally invasive way to monitor chronic diseases, glucose levels, heart rhythm, brain activity, movement or location.

Clothes hide the man: In the distant future, scientists may be able to develop an “invisibility cloak,” using metamaterials—materials with properties not found in nature. Metamaterials could be used for better imaging, for visual prosthetics such as contact lenses, or for sensors. Metamaterials might also be used to create fabric with an interesting, colorful pattern that can change an object’s image, including its color, says Andrea Di Falco, lecturer in nano-photonics at the University of St. Andrews in Scotland. Researchers there are developing Metaflex, a flexible metamaterial with electromagnetic properties.

Invisible man concept

Metamaterials often consist of metal particles smaller than light waves. To make something invisible, a metamaterial must keep light from interacting with the material itself, Dr. Di Falco explains. “If you hide the object with a cloak but you see the cloak, you haven’t done the job. You have to hide the object and hide the cloak itself.”

Researchers are therefore experimenting with ways to bend or alter light in order to hide objects. But each object needs its own unique cloak, making it feasible on a small scale but impractical for bigger objects such as people, says Dr. Di Falco. “Cloaking today is possible provided you accept some limitations,” he says. “Will we ever be able to have a Harry Potter cloak? It’s possible, but it’s very, very far off.”

 

Catherine Bolgar is a former managing editor of The Wall Street Journal Europe. 

For more from Catherine Bolgar, contributors from the Economist Intelligence Unit along with industry experts, join the Future Realities discussion.

 

Images courtesy of iStock

The Curtain Wall Industry: History, Current State, and Challenges of Façade Design

By Akio

The Evolution of Façade Design

The first building introduced with a curtain wall was the Crystal Palace in the Great Exhibition held in London in 1851.

The Crystal Palace in the Great Exhibition held in London in 1851. Appearance of Crystal Palace (right), Interior (left).

The Crystal Palace in the Great Exhibition held in London in 1851. Appearance of Crystal Palace (right), Interior (left).

The Crystal Palace in the Great Exhibition, London, 1851, pioneered façade design. For the exhibition hall for most exhibits, a greenhouse-like frame glass structure was adopted, which not only rendered the Crystal Palace the most glorious of all exhibits, but also pioneered façade design engineering.

Tweet: A brief history of the Curtain Wall industry #AEC @3dsAEC #design http://ctt.ec/DfLYd+Click to Tweet: “A brief history of the Curtain
Wall industry http://ctt.ec/DfLYd+”

After nearly a century of development, façade fabrication, in terms of type, has developed from a simple exposed-frame glass one to a semi-exposed-frame or hidden-frame, full-glass one, as well as using various metal, stone, or artificial panels; in terms of structure, the façade fabrication has developed from a simple frame one to a unitized, point-supported, double-skinned, and membrane-structured one; in addition, more energy-efficient, ecological façade panels, photoelectric façade, and intelligent façade are gathering momentum.

Obviously, façade design technology is advancing rapidly. It helps architects free their minds and enables façade design to develop from being simple and monotonous to diversified, complex, and modern.

Architectural envelopes market is mainly driven by the development of the global economy and building industry. Global economic growth promotes investment in fixed assets, and the construction demands of all kinds of public facilities, commercial buildings, and high-end residential buildings provide a foundation for the growth of global architectural envelopes markets.

From the distribution of global architectural envelopes markets, it can be seen that the U.S. and Europe are still the dominant players, combined market share accounting for about 50% in 2009.

In the meanwhile, the emerging countries represented by China and India are enjoying rapid growth of their architectural envelopes industry.

Distribution of Global Architectural Envelopes Markets in 2009

Distribution of Global Architectural Envelopes Markets in 2009

According to related statistics, China is the country with the most super high-rise buildings being constructed and planned in the world. The number of buildings in the country above 200 meters accounts for 48.5% of the total number of the buildings in the world. A large number of projects to be started in the future will demand much from the architectural envelopes industry.

It can be predicted that in the future, the U.S. and Europe will still take the lead in the design and application of architectural envelope products, and the developing countries of Asia (especially China), the Middle East, and other regions will be the main battlefield and driver of new products and application demands of the architectural envelopes globally.

Industry Challenges

The traditional building industry suffers serious productivity waste because of poor utilization of building materials, engineering rework, idling of labor, etc. According to related statistics, the value of the resources wasted in construction for a project accounts for as much as 25% of the total investment, largely wasted in façade design, fabrication, and installation.

For sustainable and healthy development of the architectural envelopes industry, it is required to analyze the reasons for the waste from the perspective of the full lifecycle of a façade fabrication, examine the challenges arising in the development of the architectural envelope industry, and grasp the opportunities of industry development.

Challenge of project management mode

Façade design (especially for complex curtain walls) is a highly professional engineering task requiring a distinguished appearance, technical functionality, and significant investment in installation planning. So, like structural design, plumbing design, and electrical design, a façade design requires special expertise.

Typically architects designing façades try to avoid a single manufacturer’s product so that the contractor can bid alternatives. This means that the architectural drawings are not coordinated with shop drawings from a manufacturer until construction has started and by that time much expert knowledge has been missed with several consequences:

  1. the final design deliverables fail to embody the progress of façade technology and new products; and
  2. the design scheme cannot meet the building energy performance requirements in an economical way.

For a close coordination between façade design and main building design, an independent third party as façade design consultants are important.

At the building schematic phase, the architects ask the façade design consultants for advice on their schematic design, so as to make possible the best building appearance; at the design development phase, the façade design consultants determines the system to-be-adopted, reserved room, etc. for the architectural envelope to provide more refined façade design drawings for façade contractors bidding.

The façade consultants should be able to produce a 3D model that incorporates the architect’s construction drawings and fabrication drawings.

Data breaking from design to manufacturing

Compared with the traditional building industry, façade design engineering is mostly based on custom manufacturing in plants. It is an industry formed from the close combination of building and industrial manufacturing. It is hoped that the accurate 3D model and 2D CAD drawings of a complex façade models can be completely sent to the numerical control cutting machines in plants.

However, due to lack of relevant cross-industry standard criteria, the data chain from façade design to manufacturing breaks, resulting in poor collaboration in problem solving, which seriously affects the industrialization of the architectural envelope industry.

Furthermore, because of the limited accuracy of many BIM software programs in parametric modeling of the components, 3D models cannot be directly applied to industrial fabrication. When an architect changes 3D models, the façade designer has to redevelop the detailed façade design and generate new fabrication drawings independently, thus causing a huge waste due to delay and rework.

Production and installation requirements of a complex curtain wall

Compared with traditional manufacturing, a façade panel has a higher degree of customization, which is reflected by not only different designs for different projects, but also different façade panels even in a project, so fast and flexible production is required as needed.

With the emergence of new materials and new technologies, and people’s constant pursuit of different building appearances, façade fabrication becomes bigger and bigger in size and increasingly complex in shape, accompanied by increasing of difficulties in field installation. In this case, if the delivery sequence and installation process are not well managed, the installation positions of façade panels may be confused, thus causing project delay and the waste of resources.

It is a pity that seamless connection of data for detailed façade design drawing, detailed joint fabrication technology, and field installation positioning (as well as realization of drawing-less and model-driven fabrication design which is a concept advocated in the machinery industry) is now beyond the capability for most BIM tools.

What we need is an accurate data integration environment incorporating building design, detailed joint design, and field installation together covering a series of management activities, including façade fabrication production, positioning, detection, cost estimation, and risk control.


Screen-Shot-2014-12-23-at-1.55.20-PM-225x300Excerpted from Technological Changes Brought by BIM to Façade Design

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