For the first time, scientists have developed a real-life ‘Star Trek’ tractor beam.
At present, the beam is miniature and is geared for use in medical testing, but potential for scaling up could exist in the future.
Light manipulation techniques have existed for decades. But this development is the first time a light beam has been used to pull objects towards the light source, the Daily Mail reports.
Specifically, the technique involves targeting a laser through a lens and onto a mirror, so that it passes back across itself in an “X” shape.
The scientific team were able to counteract the normal ‘pushing force’ that occurs when light interacts with matter, so that when the laser crossed itself the photons in the reflected beam interfered with the oncoming beam.
Normally, the solid object is pushed away by the light beam, which is made up of photons moving in one direction. That “pushing force” was first identified by German astronomer Johanes Kepler.
In experiments, scientists suspended polystyrene spheres in water directly in the laser beams’s path. The beams held the spheres in place vertically, and any pulling or pushing force moved the spheres to the left or to the right.
The technique was developed by Dr. Tomas Cizmar with colleagues at the Institute of Scientific Instruments in the Czech Republic and a team from the Scottish University of St Andrews, said The Telegraph.
As yet, it only works on particles up to five microns wide and cannot be super-sized up to pull in larger objects. Dr Cizmar, who also led the study, explains:
“The problem is that this is based on the transfer of momentum between photons (light particles) and the object, and unavoidably there is also a transfer of energy. If you imagine you would like to attract a football, the amount of energy it would transfer would be huge and it would immediately burn up the football.”
“We can probably go further but at some point the heating up would be a huge problem.”
Applications for miniature tractor beam include the precise engineering required in the building of robots, or medical testing e.g blood sample analysis.
Prof Pavel Zemanek, one of the researchers, said:
“The whole team have spent a number of years investigating various configurations of particles delivery by light.”
“I am proud our results were recognized in this very competitive environment and I am looking forward to new experiments and applications. It is a very exciting time.”