A levitated nanosphere as an ultra-sensitive sensor

said braka 5:52 AM
A tiny  and a  inside of which it hovers

as if by magic – with these simple ingredients Martin Frimmer and co-workers at the Photonics Laboratory of ETH Zurich have developed a highly sensitive sensor. In the future this device is expected to measure, amongst other things, extremely weak forces or electric fields very precisely. Now the researchers have taken a major step in that direction, as they write in a recently published scientific paper.
Nanosphere in a laser beam
Martin Frimmer, a post-doctoral researcher in the group of ETH professor Lukas Novotny, explains the working principle of a sensor very plausibly: "First I need to know how the object acting as a sensor is influenced by its environment. Anything that happens beyond that influence tells me: there is a force at work." In practice this usually means that interactions with the environment should be kept at a minimum in order to maximize the sensitivity of the sensor to the forces one wants to measure.
The scientists achieved precisely that by trapping a silica nanoparticle, whose diameter is about a hundred times smaller than a human hair, using a focused laser beam. The beam creates "optical tweezers" in which the nanosphere is held in the focus of the beam by light forces. If an additional force acts on the sphere, it is shifted from is rest position, which in turn can be measured with the help of a laser beam.


Read more at: https://phys.org/news/2017-06-levitated-nanosphere-ultra-sensitive-sensor.html#jCp