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nanotimes News in Brief

After the structure has formed, one of the two po- lymers can be dissolved away, leaving a 3-D mold that can be filled with a metal – often gold or silver. Then the second polymer is burned away, leaving a porous metal structure.

In their paper the researchers propose to create metal gyroids that allow light to pass through, but are made up of nanoscale features that interact with light, just as the atoms in glass or plastic do. In this way, they say, it should be possible to design materials with a negative index of refraction, that is, materials that bend light in the opposite direction than in an ordinary transparent material.

Special lenses made of such a material could image objects smaller than the wavelength of visible light, including proteins, viruses and DNA. Some expe- rimenters have made such superlenses, but so far none that work in the visible light range. Negative refraction materials might also be configured to bend light around an object – at least a small one – and make it invisible.

Kahyun Hur, Yan Francescato, Vincenzo Giannini, Stefan A. Maier, Richard G. Hennig and Ulrich Wiesner: Three- Dimensionally Isotropic Negative Refractive Index Mate- rials from Block Copolymer Self-Assembled Chiral Gyroid Networks, In: Angewandte Chemie Early View, October 17, 2011, DOI: 10.1002/ange.201104888: http://dx.doi.org/10.1002/ange.201104888

http://people.ccmr.cornell.edu/~uli/

11-10 :: October 2011

New research at the University of Cambridge shows how metal surfaces that lack mirror symmetry could provide a novel approach towards manufac- turing pharmaceuticals. These ‘intrinsically chiral’ metal surfaces offer potential new ways to control chiral chemistry, pointing to the intriguing possibility of using heterogeneous catalysis in drug synthesis. Such surfaces could also become the basis of new biosensor technologies. The scientists have been probing the spontaneous self-organization of a sim- ple chiral amino acid, alanine, into regular molecu- lar arrays on copper single-crystal surfaces.

Marian L. Clegg, Leonardo Morales de la Garza, Sofia Karakatsani, David A. King und Stephen M. Driver: Chira- lity in Amino Acid Overlayers on Cu Surfaces, In: Topics in Catalysis, Online First™, October 21, 2011, DOI:10.1007/ s11244-011-9758-y:

http://dx.doi.org/10.1007/s11244-011-9758-y

Yale University (U.S.) engineers recently de- monstrated that nanomechanical resonators can operate at much higher amplitudes than previ- ously thought. The results represent an advance in optomechanics, in which the force of light is used to control mechanical devices, and could have implications for future communications and sensing technologies.

“We can flip a tiny switch with light,” said Hong Tang, associate professor of electrical engineering at Yale and the principal investigator. Tang and his research team also demonstrate in the paper that