January 28, 2013
European Scientists Create Small-Scale, Star Trek-Style Tractor Beam
redOrbit Staff & Wire Reports - Your Universe Online
A small scale version of the “tractor beam” used by the starship Enterprise to tow other vessels on the television show Star Trek has been crafted by engineers from Scotland and the Czech Republic.
While light manipulation techniques are more than four decades old, this marks the first time a light beam has been used to create this type of tractor beam, even if it is at a miniature level, the University of St. Andrews claimed in a statement Friday.
Dr. Tomas Cizmar, a research fellow in the university´s school of medicine, and colleagues developed a way to create a special optical field which effectively reverses the radiation pressure of light. They discovered a method by which they can provide “negative” force acting upon microscopic particles, essentially making it so that matter is pulled towards light, not pushed away by it, as typically happens when light and objects interact.
“The scientists at St. Andrews and ISI have now demonstrated the first experimental realization of this concept together with a number of exciting applications for bio-medical photonics and other disciplines,” the UK institution explained. “The exciting aspect is that the occurrence of negative force is very specific to the properties of the object, such as size and composition.”
“This in turn allows optical sorting of micro-objects in a simple and inexpensive device. Over the last decade optical fractionation has been identified as one of the most promising bio-medical applications of optical manipulation allowing, for example, sorting of macromolecules, organelles or cells,” they added. “Interestingly, the scientists identified certain conditions, in which objects held by the ℠tractor´ beam force-field, re-arranged themselves to form a structure which made the beam even stronger.”
According to BBC News, this is not the first time that researchers have attempted to create a replica of the famed sci-fi program´s tractor beam. In 2011, researchers hailing from China and Hong Kong demonstrated how the feat could be accomplished using specially shaped laser beams, and even NASA is funding research into a similar project.
“Building on this previous research, the team constructed a beam of light and tested it on polystyrene particles with varying sizes — some were 400 nm, others were 1000 nm,” Forbes Staff Writer Alex Knapp explained.
“The researchers weren´t only able to pull them with their tractor beam, they were actually able to manipulate the beam to only pull certain particles. In other words, they could adjust the beam to only pull the 400 nm particles, then change it to only pull the 1000 nm particles,” he added.
The BBC reports that the discovery could prove useful for medical purposes. For example, a tractor beam could be used to target and attract a certain type of cells, or even an individual one.
“The practical applications could be very great, very exciting. The tractor beam is very selective in the properties of the particles it acts on, so you could pick up specific particles in a mixture,” Dr. Cizmar said. “Eventually this could be used to separate white blood cells, for example."