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What do Saturn and flowers have in common? As shapes, both possess certain symmetries that are easily recognizable in the natural world. Now, at an extremely small level, researchers from Duke University and the University of Massachusetts have created a unique set of conditions in which tiny particles within a solution will consistently assemble themselves into these and other complex shapes.

By manipulating the magnetization of a liquid solution, the researchers have for the first time coaxed magnetic and non-magnetic materials to form intricate nano-structures. The resulting structures can be "fixed," meaning they can be permanently linked together. This raises the possibility of using these structures as basic building blocks for such diverse applications as advanced optics, cloaking devices, data storage and bioengineering.

Source: http://www.physorg.com/news154190856.html

Silkworm cocoons shipped by the boxful from Japan to an optics lab at Tufts University will meet a different fate from those headed to textile factories around the world. Rather than being woven into curtains or clothing, the strong protein fibers that caterpillars once spun around themselves will be used to build optical materials that can serve as the basis for sensors and other devices. Bioengineer Fiorenzo Omenetto, who creates the devices, ultimately hopes to build implantable, biodegradable sensors that could help monitor patients' progress after surgery or track chronic diseases such as diabetes.

Omenetto realized that silk was good for more than shirts and ties, he says, when he got to talking with David Kaplan, the head of Tufts's biomedical-engineering department, with whom he shares a hallway. Kaplan turns silk proteins into cell-friendly scaffolds for engineering biological tissues, including corneal implants. The strongest natural fiber known, silk is favored by tissue engineers because it's mechanically tough but degrades harmlessly inside the body.

http://www.technologyreview.com/biomedicine/21818/

Researchers at the University of California, Berkeley, have created nanoscale particles that can self-assemble into various optical devices. By controlling how densely the tiny silver particles assemble themselves, the researchers can make several different kinds of devices, including photonic crystals. The self-assembling materials could be made cheaply and on a large scale. As a result, the silver nanoparticles could be used to make metamaterials, color-changing paints, components for optical computers, and ultrasensitive chemical sensors, among many other potential applications.

Led by Peidong Yang, a professor of chemistry at Berkeley, the researchers have demonstrated that they can use the nanoparticles to increase the sensitivity of arsenic detection by an order of magnitude. They also made a very robust kind of photonic crystal called a plasmonic crystal. These new structures are "similar to photonic crystals, but better," says Peter Nordlander, a professor of physics at Rice University, who was not involved in the work. Photonic crystals allow some wavelengths of light to pass while filtering out others. They're used commercially to coat lenses and mirrors and in optical fibers; they could also be used in optical computers.

Source: http://www.technologyreview.com/computing/21636/?a=f

Scientists say they have slowed then stopped a squirt of light in what they describe as a key step towards the future of ultra-fast computing. The technique, called 'trapped rainbow', would help optical data storage, with light replacing electrons to store information, according to their paper recently published in the journal Nature.

Controlling light would also help engineers control major nodes where billions of optical data packets arrive at the same time. By slowing some packets to let others through, rather like a traffic congestion scheme, the flow of data can be boosted.

The research, by Professor Ortwin Hess of the UK's University of Surrey and colleague Kosmas Tsakmakidis, is based on the so-called 'negative refractive index' of metamaterials.

Source: http://www.abc.net.au/science/articles/2007/11/15/2092699.htm?site=science&topic=latest

Manipulating light in a novel way, researchers at the United States Naval Research Laboratory, in Washington, DC, and the University of Alberta, in Canada, have demonstrated that light can be controlled with magnets in very small, transistor-like devices. Such switches could lead to fast, small, and efficient optical chips for cell phones, and optical communications.

The advance combines insights from two nascent research fields. In plasmonics, researchers are studying ways of guiding light along very thin metal wires to allow faster communication between devices on a chip. The other field, spintronics, involves manipulating a property of electrons called spin; in the past several years, spintronics research has enabled ultradense memory in hard drives. Now the Naval Lab and University of Alberta researchers have shown that by manipulating electron spin using magnetic fields, they can turn off and on light that's being guided through metals.

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Source: http://www.technologyreview.com/Infotech/18874/