How It Works
Tractor beam

Watch a real-life tractor beam move objects using sound waves

Tractor beam

Tractor beams have long been used in science fiction as a way for UFOs to pluck humans from Earth, or Star Trek’s Starship Enterprise to capture the enemy, but now they have finally become reality.

Scientists at the University of Bristol have invented the world’s first sonic tractor beam that can pick up and move objects using sound waves.

The device uses an array of 64 miniature loudspeakers to create high-pitch and high-intensity sound waves. These sound waves surround the object, creating a force field that keeps it in place. Then, by carefully controlling the output of the loudspeakers, the shape of the acoustic force field can be manipulated to either move or rotate the object.

So far the team have been able to create three different force field shapes, the first resembles a pair of fingers or tweezers, the second is an acoustic vortex, and the third is best described as a ‘high-intensity cage’ that surrounds the object and holds it in place.

However, rather than being used in space battles and alien invasions, this real-life tractor beam could have a wide range of useful applications here on Earth. For example, it could be used on a sonic production line to transport delicate objects and assemble them without physical contact, or a miniature version could be used to grip and transport drug capsules or microsurgical instruments through living tissue.

“We all know that sound waves can have a physical effect. But here we have managed to control the sound to a degree never previously achieved.” said Bruce Drinkwater, Professor of Ultrasonics in the University of Bristol’s Department of Mechanical Engineering. Asier Marzo, PhD student and the lead author of the paper in Nature Communications, said: “It was an incredible experience the first time we saw the object held in place by the tractor beam. All my hard work has paid off, it’s brilliant.”

Watch the tractor beam in action here:

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