British scientists create a 'tractor beam' of ultrasonic sound

A team of researchers from the Universities of Bristol and Sussex have developed the world's first functioning sonic tractor beam able to operate outside of a lab environment. The device uses 64 miniature speakers to generate high-amplitude, ultrasonic sound waves. These waves create an "acoustic hologram" (read: force field) capable of moving pea-sized objects without physically touching them. Adjusting the output of individual speakers allows the researchers to move, rotate and hold items at will.

"We all know that sound waves can have a physical effect," Bruce Drinkwater, Professor of Ultrasonics in the University of Bristol's Department of Mechanical Engineering, said in a statement. "But here we have managed to control the sound to a degree never previously achieved."

Pushing things around with sound is not a particularly new idea, however most conventional acoustic levitation systems require the object be completely enclosed by the speakers. This new system has the potential for use just about anywhere. The team recently published their findings in the journal Nature Communications.