Tuesday, August 12. 2008Bringing Invisibility Cloaks Closer
The fabrication of two new materials for manipulating light is a key step toward realizing cloaking.
By Katherine Bourzac
In an important step toward the development of practical invisibility cloaks, researchers have engineered two new materials that bend light in entirely new ways. These materials are the first that work in the optical band of the spectrum, which encompasses visible and infrared light; existing cloaking materials only work with microwaves. Such cloaks, long depicted in science fiction, would allow objects, from warplanes to people, to hide in plain sight. Both materials, described separately in the journals Science and Nature this week, exhibit a property called negative refraction that no natural material possesses. As light passes through the materials, it bends backward. One material works with visible light; the other has been demonstrated with near-infrared light. The materials, created in the lab of University of California, Berkeley, engineer Xiang Zhang, could show the way toward invisibility cloaks that shield objects from visible light. But Steven Cummer, a Duke University engineer involved in the development of the microwave cloak, cautions that there is a long way to go before the new materials can be used for cloaking. Cloaking materials must guide light in a very precisely controlled way so that it flows around an object, re-forming on the other side with no distortion. The Berkeley materials can bend light in the fundamental way necessary for cloaking, but they will require further engineering to manipulate light so that it is carefully directed. One of the new Berkeley materials is made up of alternating layers of metal and an insulating material, both of which are punched with a grid of square holes. The total thickness of the device is about 800 nanometers; the holes are even smaller. "These stacked layers form electrical-current loops that respond to the magnetic field of light," enabling its unique bending properties, says Jason Valentine, a graduate student in Zhang's lab. Naturally occurring materials, by contrast, don't interact with the magnetic component of electromagnetic waves. By changing the size of the holes, the researchers can tune the material to different frequencies of light. So far, they've demonstrated negative refraction of near-infrared light using a prism made from the material. Researchers have been trying to create such materials for nearly 10 years, ever since it occurred to them that negative refraction might actually be possible. Other researchers have only been able to make single layers that are too thin--and much too inefficient--for device applications. The Berkeley material is about 10 times thicker than previous designs, which helps increase how much light it transmits while also making it robust enough to be the basis for real devices. "This is getting close to actual nanoscale devices," Cummer says of the Berkeley prism. The second material is made up of silver nanowires embedded in aluminum. "The nanowire medium works like optical-fiber bundles, so in principle, it's quite different," says Nicholas Fang, mechanical-science and -engineering professor at the University of Illinois at Urbana-Champagne, who was not involved in the research. The layered grid structure not only bends light in the negative direction; it also causes it to travel backward. Light transmitted through the nanowire structure also bends in the negative direction, but without traveling backward. Because the work is still in the early stages, it's unclear which optical metamaterial will work best, and for what applications. "Maybe future solutions will blend these two approaches," says Fang. Making an invisibility cloak will pose great engineering challenges. For one thing, the researchers will need to scale up the material even to cloak a small object: existing microwave cloaking devices, and theoretical designs for optical cloaks, must be many layers thick in order to guide light around objects without distortion. Making materials for microwave cloaking was easier because these wavelengths can be controlled by relatively large structural features. To guide visible light around an object will require a material whose structure is controlled at the nanoscale, like the ones made at Berkeley. Developing cloaking devices may take some time. In the short term, the Berkeley materials are likely to be useful in telecommunications and microscopy. Nanoscale waveguides and other devices made from the materials might overcome one of the major challenges of scaling down optical communications to chip level: allowing fine control of parallel streams of information-rich light on the same chip so that they do not interfere with one another. And the new materials could also eventually be developed into lenses for light microscopes. So-called superlenses for getting around fundamental resolution limitations on light microscopes have been developed by Fang and others, revealing the workings of biological molecules with nanoscale resolution using ultraviolet light, which is damaging to living cells in large doses. But it hasn't been possible to make superlenses that work in the information-rich and cell-friendly visible and near-infrared parts of the spectrum. Copyright Technology Review 2008. Related Links:
Posted by Patrick Keller
in Science & technology
at
09:43
Defined tags for this entry: culture & society, dimensions, lighting, materials, research, science & technology
Arch - OSEt tiré de leur communication: Related Links:Personal comment: Déjà posté un peu plus bas, mais peut-être y jeter un oeil avec comme point de comparaison Rhizoreality? Peut-être y aurait-il un développement à mettre en commun? L'idée d'un software (OS?) qui aide à faire communiquer les ressources matérielles et digitales (immatérielles) d'une architecture dans le cadre d'un projet est en tout cas commune au deux approches logicielles. Green plug prospects
The unsightly plastic warts on our walls are sucking down terawatts of power globally each year. It’s time to put a stop to that needless energy drain by replacing dumb bricks with smart hubs -- putting a computerized stake through the hearts of our home electrical vampires. Devices that are plugged in but not in use consume between 200 and 400 terawatt hours (TWh) per year, according to the International Energy Agency. Other research pegs the not-in-use drain from 5 to 25 percent of all residential energy used in the U.S., with numbers rising. Research doesn’t divvy up between the consumption of DC-converting “wall warts” that provide juice to recharge batteries or convert power for various electronics, and the power sucked by the standby mode of televisions, microwaves and other appliances that are ostensibly “off.” But experts believe the adapters drain a significantly greater amount. DC adapters waste power through excess heat in transforming AC to DC current, through continual charging (which shortens device lifespans), and through drawing power even when nothing is attached to its DC plug, or when an attached device is powered down. Most DC converters are cheaply built, vary widely even from the same maker in efficiency, and have little of the prowess built into most other home electronics and computing peripherals. With the rise in prices of oil and the volatility of electrical prices in the U.S., there are many different efforts underway to reduce standby power, as well as shift recharging power from daytime to off-peak hours when electrical demand is low. Building a DC Ecosystem In Green Plug's model, a central hub with multiple USB ports handles anything that’s plugged into it. It checks for whether a given device has its smart technology built in, and whether the device is high- or low-power. Unless a higher charge is required, the hub uses only USB-compatible low power. In standby mode, it simply shuts off power, instead of allowing an unneeded trickle. According to company founder and CEO Frank P. Paniagua, Jr., the system works because it's a natural transition for consumers. “You don't have to change your behavior: you plug in, you save energy, you cut e-waste. Plus, it's safe: it detects what that client device is on the other side.” A related benefit of Green Plug’s approach is that the charging system has smarts. Any hardware enabled with Green Plug’s chips can transmit information about its status—number of battery cycles, current charge, and other details. Home users might use this information to see the power they’re consuming, to find out whether they can unplug a camera or phone and use it for the day, or to help with technical support when a device goes south. In offices, this information could ultimately be aggregated and used to control when power is used, as companies can often score off-peak prices from utilities, or spot faulty hardware. It’s the enabled hardware that’s the limiting factor for adoption, however. Will Manufacturers Buy In? Paniagua believes that they have a fighting chance because of regulatory and energy market changes. Manufacturers in some countries, including those in the European Union, must plan for a product’s lifecycle, and be able to accept and disassemble systems when they’ve expired. “If you manufacture it, you're going to have to take it back." (Read more about producer take-bake programs in the Worldchanging archives). Green Plug likes to emphasize the waste resulting from the adapters' short lifespans. The company estimates 3.2 billion external power supplies will be built worldwide in 2008 (with about a quarter coming to the U.S.), and that 434 million will be retired this year in just the U.S.—with only a small percentage heading into electronics recycling. Green Plug’s system—which, as their reference design demonstrates, uses water-soluble plastic and solder—easily comes apart at end-of-life, making it easy to harvest recyclable components. The Future of Charging Utilities are looking for “a real-time secure protocol” that they can work with, he said, and Green Plug hopes theirs becomes the winner. For instance, a plug-in hybrid or electric car with Greentalk inside could be scheduled through an owner’s computer to charge between 1 am and 5 am in the morning, with the device figuring out the amount of current it needs to draw to charge within that period. This could allow the kind of personally managed power shaving that utilities love: moving power usage off peak daytime hours into the night when power is cheap. Utilities that own plants also run their least-efficient, most-expensive, and most-polluting facilities last. Ultimately, the inefficiency of almost every part of electronics power usage, from cords to adapters to power supply components, has to be addressed as the cost of raw materials increases, manufacturers are more obliged to use less and accept back more, and power prices climb. Green Plug may not have the only answer, but they do have a viable one. Equipment using their technology should start appearing as soon as late this year. Glenn Fleishman is a Seattle journalist who focuses on technology, and how to overcome it. Glenn writes regularly about wireless data at Wi-Fi Networking News, and Macs at TidBITS. Image credit: Green Plug.
Posted by Patrick Keller
in Science & technology, Sustainability
at
09:22
Defined tags for this entry: energy, hardware, monitoring, research, science & technology, sustainability
Maps, Information design & architectureAt the end of last month, I attended the International Symposium on Electronic Arts (ISEA), that was held in Singapore. Although the juried exhibition of art works didn’t involve that many works on the themes of The Mobile City, the ISEA seminar had quite a few sessions on media technology and the experience of place and space. Unfortunately, there were so many parallel sessions, that I can’t pretend to come even close to a overall wrap-up of the conference. So I will just pinpoint some of the themes and works that I found interesting in a few posts in the next few days or so. If there was one trend that struck me at ISEA, it was probably the idea of data visualization as a way of making abstract or invisible cultural processes more tangible. It wasn’t only the topic of some of the artist presentations, but also the core of Lev Manovich’s inspiring closing talk. The idea is that now that we have more content and metadata than ever (Lev Manovich: this is not the era of ‘new media’ any longer, but rather the era of ‘more media’), interesting cultural forms are emerging from aggregating, analyzing and visualizing this data. Examples range from from simple tag clouds that tell us what people are talking about on the web to visualization of traffic flows in the city and systems that monitor epidemic outbreaks. In business these mappings of aggregated data are called ‘dashboards’. Lev Manovich pointed out that companies have had these dashboards for some time, but that the cultural sector is only now catching up. Right now, these mappings are becoming a new cultural form in themselves. Just look at websites like Visual Complexity , CultureVis, Infosthetics and Information Esthetics.
While all of this is interesting in itself, of course the more interesting question is how to go beyond mere ‘dashboarding’ and mapping of flows? How can we turn these display of statistics in interesting pieced of public art? And how will these maps influence our experience of both the city and our social relationships? Some examples of this trend that were shown or referred to at ISEA: Arch-OS was presented by Mike Philips. It is a system that can collects all sorts of data from a building, varying from movement in the building by analyzing the images of cctv camera’s and internet traffic on the LAN to climate data. These data streams can then be used to drive different architectural features, varying from visuals on LED screens to a giant wall sized robot that moves through the open space of an atrium. An ‘Operating System’ for contemporary architecture (Arch-OS, ’software for buildings’) has been developed to manifest the life of a building and provide artists, engineers and scientists with a unique environment for developing transdisciplinary work and new public art.
Paul Thomas showed his i-500 project, an art work that is part of a new building for Curtin University’s new Minerals and Chemistry Research and Education Buildings. It uses the Arch-Os to analyze the work of the scientists in the building and translates their activity into a public art work that is an integral part of the building. Working in close collaboration with Woods Bagot Architects, as part of the architects project team, the i-500 project team are creating a public artwork to be incorporated into the fabric of the complex with the intention to encourage building users to communicate and collaborate. The i-500 will perform a vital and integral role in the development of scientific research in the fields of nanochemistry (atomic microscopy and computer modeling), applied chemistry, environmental science, hydrometallurgy, biotechnology, and forensic science. The artworks potential is to represent the visualisation of quantitative scientific research as part of the architectural environment.
Chris Bowman and Teresa Leung are researching what looked like a ‘grammar of gps visualization systems’.
Cabspotting traces San Francisco’s taxi cabs as they travel throughout the Bay Area. The patterns traced by each cab create a living and always-changing map of city life. This map hints at economic, social, and cultural trends that are otherwise invisible. The Exploratorium has invited artists and researchers to use this information to reveal these “Invisible Dynamics.
Cascade on Wheels is a visualization project that intends to express the quantity of cars we live with in big cities nowadays. The data set we worked on is the daily average of cars passing by streets, over a year. In this case, a section of the Madrid city center, during 2006. The averages are grouped down into four categories of car types. Light vehicles, taxis, trucks, and buses.
The project aggregated data from cell phones (obtained using Telecom Italia’s innovative Lochness platform), buses and taxis in Rome to better understand urban dynamics in real time. By revealing the pulse of the city, the project aims to show how technology can help individuals make more informed decisions about their environment. Related Links:
Posted by Patrick Keller
in Architecture, Interaction design, Science & technology, Territory
at
09:01
Defined tags for this entry: architecture, conferences, data, design, generative, information, interaction design, interface, mapping, media, mobility, science & technology, software, territory, urbanism
(Page 1 of 1, totaling 4 entries)
|
fabric | rblgThis blog is the survey website of fabric | ch - studio for architecture, interaction and research. We curate and reblog articles, researches, writings, exhibitions and projects that we notice and find interesting during our everyday practice and readings. Most articles concern the intertwined fields of architecture, territory, art, interaction design, thinking and science. From time to time, we also publish documentation about our own work and research, immersed among these related resources and inspirations. This website is used by fabric | ch as archive, references and resources. It is shared with all those interested in the same topics as we are, in the hope that they will also find valuable references and content in it.
QuicksearchCategoriesCalendarSyndicate This BlogArchivesBlog Administration |