(Phys.org) —A team of researchers with members from the U.K., Scotland and the U.S. has built a functioning acoustic tractor beam in a lab—one that is able to pull objects of centimeter size. In their paper published in the journal Physical Review Letters, the team describes how they built their device, why it works and to what applications it might be put.
Tractor beams, as we all know are a staple of science fiction—a beam is emitted from a spaceship that can be used to lock on to other objects, such as another space ship, and then used to move that other object in any direction, most interestingly, in the same direction from which the beam is being emitted—pulling it in. Tractor beams seem counterintuitive as beams of light tend to push objects away, rather than attract them—but, as prior research has shown, optical tractor beams can be created at the nanoparticle level, e.g. optical tweezers. In this new effort, the research team has extended the abilities of a tractor beam by using one based on acoustics, rather than optics.