Carbon nanotubes and graphene are both made up of carbon and have unique properties. Graphene comprises an atom-thick layer of carbon atoms, while carbon nanotubes can be likened to a graphene sheet that has been rolled up to form a tube.
"If you stretch a graphene sheet from end to end the thin layer can oscillate at a basic frequency of getting on for a billion times a second," says researcher Anders Nordenfelt. "This is the same frequency range used by radios, mobile phones and computers."Possible to weigh DNA molecules
In addition to new applications in electronics, research is under way into how graphene can be used to weigh extremely small objects such as DNA molecules.Self-oscillating nanowires
"The question is whether they can also be used to produce this type of signal in a controlled and effective way," says Anders Nordenfelt. "This assumes that they themselves are not driven by an oscillating signal that, in turn, needs to be produced by something else."
In his research Anders Nordenfelt carried out a mathematical analysis to demonstrate that it is possible to connect the nanowire with a fairly simple electronic circuit, and at the same time to apply a magnetic field and thus get the nanowire to self-oscillate mechanically.
"At the same time we're converting a direct current to an alternating current with the same frequency as the mechanical oscillation," says Anders Nordenfelt.Harmonics – a way of reaching even higher frequencies
"An unexpected and very interesting result is that the method I've proposed can be used to get the nanowire to self-oscillate in one of its harmonics," says Anders Nordenfelt. "You can change the harmonic by altering the size of one or more of the electronic components."In principle, there are an infinite number of harmonics with unlimited high frequencies, but there are practical limitations.
This area is particularly interesting as it lies on the boundary between microwaves and infrared radiation that, to date, has been the subject of relatively little research. It is an area that has been too fast for electronic circuits, but too slow for optical circuits.
"We can't get these really high frequencies with my method as things stand, but it could be something for the future," says Anders Nordenfelt.
The thesis has been successfully defended.For more information, please contact: Anders Nordenfelt
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Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
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In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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