While optical tweezers have been used to move particles for years, physicists haven't been able to move them very far -- only a few millimeters at best -- but a few Australian researchers are making new strides. 

Scientists at the Australian National University have just announced that they are developing a method which can move objects much further – over a distance of a meter and a half – powered by light.

According to team leader Professor Andrei Rode, the group of researchers used a hollow laser beam to trap light-absorbing particles in a “dark core”.  

The device works by shining its beam around tiny glass particles. The hollow laser beam heats up the air surrounding the particles, but the dark center of the beam is directed toward them which allows the particles to remain cool. As they gravitate and are drawn toward the laser beam, the particles are pushed back toward the center by heated molecules. Particle speed and direction can be manipulated by changing the brightness of the beams.

"When the small particles are trapped in this dark core, very interesting things start to happen. As gravity, air currents and random motions of air molecules around the particle push it out of center, one side becomes illuminated by the laser while the other lies in darkness," said Rode.

Since the laser beam requires the use of heated gas, it won't work in outer space, but Rode said that there are other practical applications that can be considered for use here on Earth. “These include, directing and clustering nano-particles in air, the micro-manipulation of objects, sampling of atmospheric aerosols, and low contamination, non-touch handling of sampling materials."

The laser beam could also be used for the transport of dangerous substances and microbes, in small amounts. Rode added that the hollow laser could be used to move particles as much as 30 feet away.

The team's plan to continue work on the project include increasing size and distance of objects in the very near future.

According to the ANU website, a full article about the team's laser beam research will be available online starting September 23 through the university's science magazine, Science Wise.