Darth Vader's Death Star and Captain Kirk's Starship Enterprise both had one. Now the tractor beam, that science fiction favourite deployed to memorable effect in numerous films and television series over the years, has finally arrived on Earth.

A team of researchers at two British universities has created the world's first fully functioning sonic tractor beam, capable of suspending, moving and manipulating small objects using only the power of sound waves.

Previous studies have shown that tractor beam technology is possible, but the new study is significant as it is the first time an object has been successfully held and controlled in mid-air. High-amplitude sound waves were used to generate an "acoustic hologram" capable of suspending a 4mm-wide polystyrene ball in space.

The technique, refined by scientists at the Universities of Bristol and Sussex, has a wide range of applications and could in the future be used to manipulate objects inside the human body without the need for an invasive medical procedure.