Technology Trends

Researchers at the University of Toronto (U of T) have designed an infrared-sensitive material made of nanocrystals so small they were able to tune them to catch the Sun’s invisible rays. In “Nanotechnologists’ new plastic can see in the dark,” you’ll discover that it’s the first time that a light-sensitive material works in the invisible light spectrum. This opens the way to a broad range of applications, from clothing to digital cameras that work in the dark. But the real breakthrough is that it will permit to catch five more times energy from the Sun, up to 30 percent from the 6 percent achieved today by the best plastic solar cells. Hats off to these researchers…

Here is the somewhat lyrical opening paragraph of the U of T news release.

Imagine a home with “smart” walls responsive to the environment in the room, a digital camera sensitive enough to work in the dark, or clothing with the capacity to turn the sun’s power into electrical energy. Researchers at the University of Toronto have invented an infrared-sensitive material that could shortly turn these possibilities into realities.

Professor Ted Sargent, from Nortel Networks and U of T, explains the process.

“We made particles from semiconductor crystals which were exactly two, three or four nanometres in size. The nanoparticles were so small they remained dispersed in everyday solvents just like the particles in paint,” explains Sargent. Then, they tuned the tiny nanocrystals to catch light at very short wavelengths. The result — a sprayable infrared detector.

Existing technology has given us solution-processible, light-sensitive materials that have made large, low-cost solar cells, displays, and sensors possible, but these materials have so far only worked in the visible light spectrum, says Sargent. “These same functions are needed in the infrared for many imaging applications in the medical field and for fibre optic communications,” he says.

You might think that concrete is a boring material. Not at all. In a very well-documented article, “Concrete Nation,” Science News tells us how the limits of this humble material are being pushed. You can now find concrete that bends like metal and which is five times as strong as regular concrete without any reinforcing steel bars. Or you can use concrete which doesn’t need a vibration machine to remove the air bubbles inside, which can save lots of time during construction. There are also translucent concrete or concrete incorporating transparent elements, allowing to build floors lit from below. And by adding titanium dioxide to cement, you obtain a self-cleaning concrete that remains the same color for centuries and can even clean the air by breaking down dangerous pollutants. Fascinating, isn’t?

Before going further, let’s start by some illustrations. The pictures and the legends below come from the site of a current exhibit at the National Building Museum in Washington, D.C., Liquid Stone: New Architecture in Concrete (Macromedia Flash needed).

Below are computer-generated images of the hypothetical Mound Builder Museum designed by Building Studio from Memphis, Tennessee (Macromedia Flash needed).

And this one shows another museum, the MUCEM, in Marseille, France, which will be completed by 2009.

Now, let’s look at a concrete that bends like metal.

For instance, consider some of the new materials developed by concrete giant Lafarge, headquartered in Paris.

Vic Perry leads the company’s North American operation producing Ductal, one of Lafarge’s newest concrete products (Macromedia Flash needed). Unlike regular concrete, which is brittle and can rupture suddenly under a heavy load, Ductal can bend. “It will deflect and show signs of cracking before it fails,” says Perry. “You can see in advance that you’ve got a problem.”

What’s more, Ductal is five times as strong as regular concrete. That extra oomph comes from the addition of small fibers dispersed throughout the matrix. These fibers, made of either steel or polymer, reinforce the concrete and eliminate the need for reinforcing steel bars, or rebar. A bridge made out of Ductal can be lighter and thinner than a traditional bridge, Perry says.

Because of an aging workforce, there is also the need to reduce the amount of labor during construction.

In response to this concern, Lafarge has developed Agilia. According to the company, laying a 60-cubic-meter slab of regular concrete — enough for a floor in an office building — requires eight people and takes about 8 hours. Placing the same-size slab of Agilia could require as few as two people and take a couple of hours.

Normally, after concrete is poured, the mason passes a vibrating machine over the surface to squeeze out all the air bubbles. It’s a loud and time-consuming process. However, Agilia contains a mix of additives: superplasticizers that keep the concrete fluid and other chemicals that cut down on the water needed. These enable the concrete to consolidate under its own weight without mechanical vibration.

Other concerns, such as global warming, also lead to concrete innovations. Do you know that the cement industry produces 7% of the global human production of carbon dioxide? There are now efforts to replace cement by ‘greener’ materials. And new kinds of concrete are specifically designed to reduce pollution.

Scientists at the Italcementi Group in Bergamo, Italy, have developed a self-cleaning concrete that keeps buildings from turning black from pollutants in the atmosphere. Luigi Cassar and his colleagues at the research branch of Italcementi made the concrete by adding particles of the white pigment titanium dioxide to the cement component.

When titanium dioxide absorbs ultraviolet light, it becomes highly reactive and breaks down pollutants that come into contact with the concrete’s surface. The reactive material can kill bacteria and fungi and also break down pollutants such as nitric oxide, sulfur dioxide, and many volatile organic compounds that contribute to concrete’s darkening.

After reading about all these innovations, do you still think that the ubiquitous concrete is boring?

Sources: Alexandra Goho, Science News, Vol. 167, No. 1, Jan. 1, 2005, p. 7; and various websites

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Transparent electronics is an emerging technology which aims to produce invisible electronic circuits. Now, researchers from Oregon report they made a major advance in transparent electronics. Their zinc-tin-oxide ‘thin-film’ materials are amorphous, physically robust, chemically stable and cheap to produce at just above room temperature. These new materials and transistors offer many new possibilities for consumer electronics, transportation, business and the military. Even if these transparent transistors don’t show up inside your next computer, they might soon appear in flat panel screens, flexible electronics devices you’ll carry with you, and even in your car windshields. But it should take some time. Read more…

Before going further, please remember that the following quotes are written in PR jargon. So read them with a grain of salt…

Researchers at Oregon State University (OSU) and Hewlett Packard have reported their first example of an entirely new class of materials which could be used to make transparent transistors that are inexpensive, stable, and environmentally benign. This could lead to new industries and a broad range of new consumer products, scientists say.

This is a significant breakthrough in the emerging field of transparent electronics, experts say. The new transistors are not only transparent, but they work extremely well and could have other advantages that will help them transcend carbon-based transistor materials, such as organics and polymers, that have been the focus of hundreds of millions of dollars of research around the world.

It’s time for more ‘technical’ details about these zinc-tin-oxide thin film transistors.

They are amorphous, meaning they have no long range crystalline order, which helps to keep processing costs a great deal lower. They are also physically robust — hard to scratch, chemically stable, resist etching, and have a very smooth surface. They are made from low cost, readily-available elements such as zinc and tin, which raise no environmental concerns.

“What has been most surprising, however, is that we can make high quality oxide transistors with these new materials at just above room temperature,” said John Wager, a professor of electrical and computer engineering at OSU. “Simply put, that’s shocking. Most integrated circuits made today, by comparison, are produced at temperatures between 700-1,100 degrees centigrade.”

As you probably guessed by now, this technology is a nascent one. But researchers are very optimistic about future uses, for example with gas sensor systems.

These sensors are used extensively in automotive and other mechanical applications, and the new zinc-tin oxide transistors might allow the creation of a new type of gas sensor whose sensitivity is electronically controlled over a wide dynamic range.

In the field of transparent applications, there should be uses in consumer electronics, transportation, business and the military. Automobile windshields could transmit visual information. Glass in almost any setting could also double as an electronic device, possibly improving security systems or transparent displays. The military is extremely interested in research of this type because of possible uses in sophisticated technology or fighting equipment.

For more information about transparent electronics, you should visit John Wager’s home page at Oregon State’s School of Electrical Engineering and Computer Science. Here is a direct link to his research activities.

The latest work done by Wager and his colleagues has been published online by Applied Physics Letters on December 23, 2004. Here is a link to the abstract of this paper named “High mobility transparent thin-film transistors with amorphous zinc tin oxide channel layer.”

A previous paper about these see-through transistors was published last year by the Journal of Physics D: Applied Physics. Here is a link to this full paper, named “Spin-coated zinc oxide transparent transistors,” from which the above illustration was extracted.

Sources: Oregon State University news release, via EurekAlert!, December 28, 2004; Applied Physics Letters, Volume 86, Issue 1, January 3, 2005; Journal of Physics D: Applied Physics, Volume 36, Number 20, October 21, 2003; and various websites

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In this must-read article, MIS, from Australia, asserts than in 10 to 15 years, we’ll be unable to use today’s technologies to build electronic devices always smaller and more powerful. Instead, three disruptive technologies will converge and deeply change our lives: nanotechnology, sensors and wireless technology. The author explains how this will influence molecular computing or quantum information processing. She also describes future advances in robotics, including nanobots. And the transportation industry will welcome the arrival of skycars, which are under development today. But will we travel anymore when holographic videoconferencing tools will be available? Please take a moment to check this fascinating article or read more below…

If nanobots and skycars sound more like sci-fi than a sane view of the future, then you may need to reprogram your mindset. Helene Zampetakis reports on the technology that will shape our lives in the decades to come.

A trio of disruptive technologies will converge over the next five to 15 years to overtake our incumbent systems and create new competencies that will profoundly change the way we organise our lives and the way we do business.

The driving principles behind modern technology are running out of steam: it is becoming prohibitively costly to continue to shrink technology, while Moore’s Law, which postulates the doubling of computer power every 18 months, is reaching its physical limits under current processes.

Luckily, help is coming with the convergence of three technologies.

But research that is underway today is expected to usher in a new technological era. Dubbed ‘embedded connectivity’ by Bob Hayward, vice-president and research fellow at Gartner, it will draw strength from nanotechnology, sensors and wireless technology.

The embedded world of the future will harness the power of billions of microprocessors on a single device, wirelessly connected to others, that can read the environment and react accordingly. Scientists portray a future in which we attach these devices to our bodies to communicate, set them loose on our streets to do menial tasks, and embed them in the commonplace objects of our lives to address our daily requirements.

The underlying foundation for this new era of embedded connectivity is nanotechnology, which is based on the manipulation of molecules less than 100 nanometres in size. “Nanotechnology means that rather than taking a chunk of silicon and carving it down to size, we build from the bottom up by assembling single molecules and atoms,” says Dr Terry Turney, director of CSIRO’s nanotechnology centre.

Zampetakis then looks at electronic circuitry and how it will be transformed by molecular self-assembly technology. She also describes future quantum information processing and wireless networks of sensors.

Now, let’s look at what she says about robotics.

It will be at least 20 years before we see microscopic ‘nanobots’, the much-hyped molecular manufacturing systems that have generated sci-fi like fears of mutating swarms running amok. But miniature robots are in fact under serious investigation.

In 2000, for example, MIT’s Bioinstrumentation Laboratory unveiled the Nanowalker, a sugar-cube sized prototype of the first autonomous nanorobot. The Nanowalker is able to move with great precision at a speed of about 4,000 steps a second and communicate wirelessly to a central computer.

Nanorobots will eventually construct materials atom by atom to create products that do anything from surveillance to in vitro navigation.

Larger robots will also be present and will become more independent.

Currently robots operate in controlled environments designed around them, such as car assembly plants, but the next generation of machines will be designed to function in a less structured world and to cope with unexpected changes to their environment.

Robotics research today centres around embedding these devices with fuzzy logic skills using sensors that will allow them to perceive and respond. Dr Peter Corke, autonomous systems team leader at CSIRO, says we could expect to see this class of machine delivering mail or medication or stacking store shelves at low cost to replace human labour in five to 10 years from now. Larger versions could be used down mines; and indeed this research is principally funded by the mining industry, along with organisations interested in flying robots that can inspect assets such as power lines.

And after decades of science-fiction stories, skycars will finally be there.

These will let us travel “when and where but especially how we wish”, according to Mark Moore, personal air vehicle sector manager for NASA’s Vehicle Systems Program.

NASA’s area of focus is a skycar (or personal air vehicle — PAV) designed not for getting about the city, but for travelling at high speeds for distances of between 160kms to 800kms. That would allow people to live in regional areas and commute into urban airfields for work.

Over the next decade Moore expects to see flying cars priced at less than US$100,000 using automated functionality based on NASA’s EquiPT (Easy-to-use, quiet Personal Transportation) technology set.

Moore says an obstacle to PAVs has been the intensity of training required to fly them, so automation is critical. The goal is to have the vehicle controlled by a computerised brain that senses and responds to weather conditions or other crafts in the vicinity, and compensates for technical failures.

And did you know you could order a skycar today? Moller International, based in California, is developing the M400 Skycar and hopes it will be certified by 2006. And you can purchase a 4-passenger Skycar today for a cool $995,000!

But will we travel with the arrival of the next generation of videoconferencing tools?

The synergy of vastly increased bandwidth, three-dimensional video projection and interactive holography systems is expected to change the way we collectively communicate, according to James Anderson, country manager of Polycom.

Videophones as a standard business tool are a decade away but it will be more like 20 years before research from bodies such as MIT’s Spatial Imaging Group or 3D visualisation company, Actuality Systems, yields practicable holographic videoconferencing. By then, however, “we’ll be looking at life-size holograms in 3D that can move around the room in full motion”, says Anderson.

Finally, Zampetakis looks at changes in information technology likely to happen in the next five to ten years.

Now, I have a question for you. Is this message from the future a one you like? Personally, I do.

Source: Helene Zampetakis, Managing Information Strategies, Australia, December 17, 2004; Moller International

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Carbon nanotubes, which can have useful electrical or optical properties, are typically grown using chemical vapor deposition techniques. During this process, amorphous and useless carbon layers are also produced, meaning that a post-growth purification process is needed. Not anymore. According to this article from Technology Research News (TRN), Japanese researchers have successfully used water to get rid of these impurities. The idea of using water to clean carbon nanotubes is so simple that I’m amazed that nobody thought about it before. Anyway, this method, which eliminates the post-growth purification process, still needs some improvements and will not help to mass produce carbon nanotubes before at least five years. There were several other announcements about nanotechnology achievements in the last two weeks, so read more…

Here are the opening paragraphs of the TRN article.

Washing away impurities with water turns out to be as good for growing carbon nanotubes as it is for keeping a clean house.

Carbon nanotubes show great promise as building blocks for molecular machines, high-speed electronics and super-strong materials, but it has proven difficult to reliably grow large amounts of pure carbon nanotubes and to keep the growth process orderly.

And here are the essential details of this new cleaning process.

Researchers from the Japanese National Institute of Advanced Industrial Science and Technology (AIST) have added water to the standard method of manufacturing carbon nanotubes to produce tall, dense, vertically-aligned stands of pure nanotubes.

The purity of the nanotubes makes the usual post-growth purification process unnecessary. This makes the method quicker, less expensive and less likely to damage the nanotubes than existing processes, said Kenji Hata, a senior researcher at the Japan National Institute of Advanced Industrial Science and Technology. Nanotubes produced using the method are orderly and pure enough for use in many fields, including biology, medical implants, chemistry, electronics and magnetics research, he said.

Please read the full article TRN article for other details and keep in mind that this method for growing carbon nanotubes is still a work in progress.

The method could be used to mass produce carbon nanotubes within five years, and for practical applications within ten years, said Hata.

The research work has been published by Science on November 19, 2004 under the name “Water-Assisted Highly Efficient Synthesis of Impurity-Free Single-Walled Carbon Nanotubes.” Here is a link to the abstract.

We demonstrate the efficient chemical vapor deposition synthesis of single-walled carbon nanotubes where the activity and lifetime of the catalysts are enhanced by water. Water-stimulated enhanced catalytic activity results in massive growth of superdense and vertically aligned nanotube forests with heights up to 2.5 millimeters that can be easily separated from the catalysts, providing nanotube material with carbon purity above 99.98%. Moreover, patterned, highly organized intrinsic nanotube structures were successfully fabricated. The water-assisted synthesis method addresses many critical problems that currently plague carbon nanotube synthesis.

This column is getting too long, so you’ll find other references in this sidebar, “Nanotech News Roundup #1.” Maybe there will be another edition in about a couple of weeks.

Sources: Eric Smalley, Technology Research News, December 1-8, 2004; Science, November 19, 2004

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Biologists and physicists from the University of California, Santa Barbara (UCSB), have discovered living nanoscale ‘necklaces’. They were studying “microtubules from the brain tissue of a cow to understand the mechanisms leading to their assembly and shape.” And unexpectedly, they found that some divalent cations pushed these microtubules, which are nanotubes derived from cell cytoskeleton, to assemble into ‘necklaces’ of different shapes. Now they think their discovery could be used to deliver drugs or genes. These ‘necklaces’ also could be used to build biosensors or new optical nanomaterials. Read more…

Here is the description of the discovery.

The scientists studied microtubules from the brain tissue of a cow to understand the mechanisms leading to their assembly and shape. Microtubules are nanometer-scale hollow cylinders derived from cell cytoskeleton. In an organism, microtubules and their assembled structures are critical components in a broad range of cell functions — from providing tracks for the transport of cargo to forming the spindle structure in cell division. Their functions include the transport of neurotransmitters in neurons. The mechanism of their assembly within an organism has been poorly understood.

the researchers report the discovery of a new type of higher order assembly of microtubules. Positively-charged large, linear molecules (tri-, tetra- and penta-valent cations) resulted in a tightly bundled hexagonal grouping of microtubules — a result that was predicted. But unexpectedly, the scientists found that small, spherical divalent cations caused the microtubules to assemble into a “necklace.” They discovered distinct linear, branched and loop shaped necklaces.

And what can we expect from these living necklaces?

The scientists envision applications based on both the tight bundle and living necklace phases. For example, metallization of necklace bundles with different sizes and shapes would yield nanomaterials with controlled optical properties.

A more original application is in the area of using the assemblies — encased by a lipid bilayer — as drug or gene carriers where each nanotube may contain a distinct chemical, as noted by the team. In delivery applications the shape of the bundle determines its property. For example, the linear necklace phase with its higher surface to volume ratio would have a larger contact area and a faster delivery rate compared to the tight bundle phase.

The research work has been published online by the Proceedings of the National Academy of Sciences under the intriguing title “Higher-order assembly of microtubules by counterions: From hexagonal bundles to living necklaces.” It should appear in the printed version on November 16, 2004. Here is a link to the abstract of the paper.

For more information, you can visit the Materials Research Laboratory website at UCSB, and more specifically, the Biomaterial Microstructures page.

Sources: UCSB news release, via EurekAlert!, November 8, 2004; and various other websites

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