In the “Star Trek” series, the crew of the U.S.S. Enterprise sometimes had to tow another spaceship. To pull of this amazing feat, the Enterprise turned to a “tractor beam,” which used a beam of light to attract objects.
Now, a team of scientists from the University of St Andrews and the Institute of Scientific Instruments in the Czech Republic have developed a real-life tractor beam. Scientists note that although light manipulation techniques have been around since the 1970s, this study marks the first time that a light beam has been used to pull objects towards the light source, even if it is being accomplished at a microscopic level.
Scientists have discovered a way to create a special optical field that efficiently reverses radiation pressure of light, according to a news release from the University of St Andrews. Scientists posit that this new technique could lead to more efficient medical testing, such as in the analysis of blood samples.
“Because of the similarities between optical and acoustic particle manipulation we anticipate that this concept will provide inspiration for exciting future studies in areas outside the field of photonics,” said Dr Tomas Cizmar, Research Fellow in the School of Medicine at the University of St Andrews, in a statement.
The research team found a technique which will give them the ability to provide “negative” force acting upon microscopic particles. Usually when matter and light interact the solid object is pushed by the light and transported away in the stream of photons. According to scientists, this radiation force was first recognized by Johanes Kepler when seeing the tails of comets point away from the Sun.
In recent years, scientists realized that there is a space of parameters when this force reverses. Scientists demonstrated the first experimental evidence of this concept along with a number of other applications for bio-medical photonics.
Scientists note that the occurrence of negative force is extremely specific to the properties of the object, such as size and composition. This allows optical sorting of micro-objects in an inexpensive device. Scientists believe that optical fractionation is one of the most promising bio-medical applications of optical manipulation, giving them the ability to sort cells or macromolecules.
“These methods are opening new opportunities for fundamental phonics as well as applications for life-sciences,” said Dr Oto Brzobohaty of the ISI.
Scientists discovered that in certain conditions, the objects held by the tractor beam force field, re-arranged themselves to from a structure which made the beam even stronger.
“The whole team have spent a number of years investigating various configurations of particles delivery by light,” said Professor Pavel Zemanek, also of the ISI. “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.”
While it will be quite some time before NASA or any other space agency will be able to tow a spaceship using a tractor beam, Forbes notes that NASA is actively working to create tractor beams as a way for their rovers to collect samples.
Photo credit: Chris Devers.