GENEVA, July 24 (Xinhua) -- Researchers at the Swiss federal technology institute ETH Zurich said Tuesday that they have made a nanoparticle turn around its own axis a billion times a second.
"Nothing in the world rotates faster than a tiny particle in a laboratory at the Institute for Photonics in Zurich," said the ETH Zurich in a statement.
From such measurements of rotating particles, the scientists hope to obtain new insights into the behavior of materials under extreme stress, it said.
Professor Lukas Novotny and his collaborators at the Institute for Photonics manipulated a minuscule piece of glass only a hundred nanometers in size. That is one thousand times smaller than a hair.
It was manipulated so to make it turn around its own axis more than a billion times a second. It takes considerable technical effort to make an object rotate that fast, said the researchers.
"To do so, we trap the glass particle in a vacuum apparatus using so-called optical tweezers," explained Rene Reimann, a researcher in Novotny's laboratory.
Optical tweezers are created by a strongly focused laser beam, where the glass particle is levitated by light forces at the focus of the beam. This allows the scientists to eliminate any direct mechanical contact with the outside world, which would lead to friction losses.
Moreover, the pressure in the apparatus is a hundred million times lower than the normal air pressure at sea level. This means that only very rarely do single air molecules collide with the particle, slowing it down slightly in the process, said the researchers.
For nanotechnology, such measurements are important because the properties of materials at the nanoscale can differ drastically from those of larger objects.
That is partly due to the extreme purity of nanoparticles and the virtual absence of defects, the scientists said.
The results of the research were recently published in the scientific journal Physical Review Letters, said ETH Zurich.
