Posted By Staff Writer :YBM
Star Trek fans are going to be excited to hear the announcement that researches from the Australian National University have built a device that can move small particles a meter and a half using only the power of light. There has been optical tweezers that can move particles a few millimeters for years, this device is much more advanced.
Andrei Rhode, a researcher involved with the project, said that existing optical tweezers are able to move particles the size of a bacterium a few millimeters in a liquid. Their new technique can move objects one hundred times that size over a distance of a meter or more.
"With the particles and the laser we use, I would guess up to 10 meters in air should not be a problem. The max distance we had was 1.5 meters, which was limited by the size of the optical table in the lab,"Rhode said.
The device works by shining a hollow laser beam around tiny glass particles. The air surrounding the particle heats up, while the dark center of the beam stays cool. When the particle starts to drift out of the middle and into the bright laser beam, the force of heated air molecules bouncing around and hitting the particle's surface is enough to nudge it back to the center.A small amount of light also seeps into the darker middle part of the beam, heating the air on one side of the particle and pushing it along the length of the laser beam. If another such laser is lined up on the opposite side of the beam, the speed and direction the particle moves can be easily manipulated by changing the brightness of the beams.Rhode said that their technique could likely work over even longer distances than they tested.
"With the particles and the laser we use, I would guess up to 10 meters in air should not be a problem. The max distance we had was 1.5 meters, which was limited by the size of the optical table in the lab,"Rhode said.
This technique requires heated gas to push the particles around, so it can't work in the vacuum of outer space like the tractor beams in Star Trek. But on Earth there are many possibilities for the technology to touch on. The meter-long distances that the team was able to move the particles could lead to new applications such as transport of dangerous substances and microbes for sample taking and biomedical research. Far as developing the technology to move a ship like on Star Trek, right now, we just have to keep our fingers crossed.
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