Graphite had already been extensively studied. German physicist Martin Dienwiebel was therefore extremely surprised when he discovered a completely new effect in this well-known lubricant. During research into the frictional properties of the material, he discovered that the frictional force almost completely disappeared at a certain moment.
Dienwiebel only intended to test the new friction force microscope he had developed. The Tribolever is a raster microscope which can measure frictional forces of just a few picoNewtons in three spatial dimensions. With his new instrument Dienwiebel first of all studied the frictional properties of graphite.
Graphite consists of carbon atoms arranged in layers one above another. The carbon atoms in a graphite layer form a sort of undulating landscape, which is similar to an egg box. The different layers can slide over each other. However, resistance can occur during the sliding process if the hills of one layer fit exactly into the valleys of another layer. Yet if the two layers are rotated with respect to each other, there are always points within the contact surface where the hills touch each other. As a result of this the two layers cannot collapse into each other and the resistance is overcome. The researcher has termed this phenomenon superlubrication.
Nalinie Moerlie | alfa
UNH scientists help provide first-ever views of elusive energy explosion
16.11.2018 | University of New Hampshire
NASA keeps watch over space explosions
16.11.2018 | NASA/Goddard Space Flight Center
Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.
Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...
Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.
Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...
Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.
In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...
On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.
When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure
Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...
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16.11.2018 | Life Sciences
16.11.2018 | Life Sciences