Resourceful nanocubes make great light absorbers Researchers have shown that nanocubes separated from a metal surface by a nanoscale dielectric film absorb light at specific wavelengths. Moreover, the color absorbed can be altered simply by changing the environment of the nanocubes. A device of this kind, which is both cheap and easy to produce, could be used to detect a change in temperature or the presence of a particular compound. In addition, when the deposition surface is heated, the cubes become light emitters. When coupled with a photovoltaic device, they could turn heat into electricity. 39 Artist’s impression of silver nanocubes deposited on a gold film. Nature December 2012 online Virtual design on the nanoscale Computer specialists have developed a software program that can be used to calculate and view in real time the electronic structure of a molecule when its geometry is modified on screen. The user can thus follow molecular dynamics “live”, or construct stable configurations. This innovation is part of the SAMSON software program, whose aim is to develop a device for the virtual analysis and design of nanosystems. It is also a remarkable teaching tool that is already being used in French secondary schools. Opening the way to artificial nanomuscles Nature produces a large number of “molecular” machines that work in unison and underpin essential functions in living organisms. Taking inspiration from this, chemists have succeeded in making an assembly of nanomachines that, like muscle fibers, are capable of producing a coordinated contraction movement of around ten micrometers. They did this by assembling thousands of polymer chains, each able to contract by one nanometer under the effect of pH. These remarkable results could lead to applications ranging from the design of artificial muscles to robotics and information storage. Angewandte Chemie International Edition October 2012 online Flexible high-frequency graphene-based transistors At around 8 GHz, a new record frequency for organic transistors has just been achieved thanks to a novel production process in which single-layer graphene sheets, in solution in a conductive ink, are deposited on a polymer substrate under the effect of an electric field. This technique makes it possible to obtain high graphene densities locally, which is essential for achieving high-frequency performance. This augurs well for applications in organic electronics, such as flexible displays. Nano Letters January 2012 online 2012 A year at CNRS
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