The wires are made of carbon nanotubes that measure approximately 2 nanometers in diameter. The researchers have published an article on the subject this week in the scientific journal Nano Letters.
The researchers at the Kavli Institute of Nanoscience Delft and the FOM Foundation (Fundamental Research on Matter) made the small wires from carbon nanotubes, measuring approximately 1 micrometer long and approximately 2 nanometres in diameter. The tubes were attached to electrodes and initially placed above a layer of silicon oxide. This layer of silicon oxide was then partially etched away with acid, which caused the tubes to detach and hang.
A layer of silicon is contained beneath the silicon oxide. A strong and frequently variable alternating current is applied to this layer, which causes the hanging nanotubes to vibrate. The suspended tube is alternately attracted and repelled. The largest measured deviation for one tube was 8 nanometres. The distance of the nanotubes to the layer of silicon influences the electrical capacity to the layer of silicon. The movement of the nanowires is derived from these changes in capacity.
When the frequency of the applied current approaches the level of the suspended tube's eigenfrequency, it begins to vibrate more powerfully. The order of magnitude of these frequencies amounts to a few tens of MHz. By varying the strength and frequency of the applied current, the research group led by Professor Herre van der Zant succeeded in transposing the wire from a freely suspended state, to a state in which it is taut and vibrates. Van der Zant: "And as such it is like tightening a piano wire or guitar string. You can, as it were, tune the wire."
The Delft researchers have developed a model that can satisfactorily predict the vibrations of the nanotubes. The vibrating nanotubes are not only interesting from a scientific standpoint; in future they can also be used for other specific applications. Van der Zant identifies one possibility as a hypersensitive mass sensor. "The nanotubes are extremely lightweight. If you suspend something from the tube that is also extremely lightweight, like a virus, then the change in mass is rendered by a different vibration pattern. From this, you can determine the size of the extra mass and deduce if it involves the virus concerned." The vibrating tubes may also be of interest for GSM-related applications (which now use resonators that vibrate in the GHz-field.)
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30.03.2017 | NASA/Goddard Space Flight Center
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30.03.2017 | Max-Planck-Institut für Struktur und Dynamik der Materie
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
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.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
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...
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