The days of using Star Trek images to depict tractor beams are over, the real thing is here.

Scientists in Spain have shown off a real, working tractor beam moving objects through the air.

The Public University of Navarre has created a sonic tractor beam that can grab and move tiny objects about. The scientists behind the breakthrough say this could be used to operate microsurgical instruments inside patients' bodies. It could also be used to direct specific drugs at certain damaged tissues in the body.

In the video the sonic unit is shown moving 3mm polystyrene beads. While these weigh very little they're still large enough to see with the human eye, making this one of the most impressive examples yet.

The technology works by using an array of speakers, essentially. These create an acoustic hologram made using interfering sound waves. When the peaks of two waves meet, it creates an area of great amplitude while a meeting of two peaks creates a trough – essentially making a way of 'holding' objects.

This 3D hologram is made into a cage or bottle shape to hold objects. It could also be made into tweezers or rotating spirals to lift, grab, spin and nudge particles around.

The team says they could manipulate much heavier objects but are focusing on medical applications right now.

When this technology will get used in a medical situation is still unclear as it's early days yet.