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
Efficient time synchronization of sensor networks by means of time series analysis
24.01.2017 | Alpen-Adria-Universität Klagenfurt
Ultra-precise chip-scale sensor detects unprecedentedly small changes at the nanoscale
18.01.2017 | The Hebrew University of Jerusalem
A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...
For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.
According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...
An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...
Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...
Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.
While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...
19.01.2017 | Event News
10.01.2017 | Event News
09.01.2017 | Event News
24.01.2017 | Physics and Astronomy
24.01.2017 | Life Sciences
24.01.2017 | Health and Medicine