Science fiction becomes reality with tractor beam



The tractor beam, a staple of science fiction, including Star Wars and Star Trek, in which it is used to remotely grab spaceships and other things, is entering the realm of reality. Researchers said yesterday they had developed a tractor beam using high-amplitude sound waves to levitate, move and rotate small objects without making contact with them.They used sound waves from 64 miniature loudspeakers called transducers to create what they called "acoustic holograms" to control an object without touching it.Describing possible medical applications , lead author Asier Marzo of the University of Bristol said: "Sound cannot travel through the void of space but it can travel through water or human tissue. This potentially enables the manipulation of clots, kidney stones, drug capsules, microsurgical instruments or cells inside our body without any incision."