Tractor Beams Harness The Power Of Acoustic Holograms To Make Sci-Fi A Reality

With news of a working tractor beam, Earth is officially in the future. A futuristic innovation once thought to be relegated to the realm of science-fiction, researchers from the University of Bristol and the University of Sussex have used acoustic holograms to manipulate an object from across the room.

As scientists are wont to do, the sonic tractor beam has a more technical -- but, still cool sounding -- name. Acoustic holographic elements are what researchers harnessed to move a small bead around in an experimental setting. The tractor beam setup requires 64 miniature loudspeakers to create high-intensity sound waves. Researchers manipulate the sound waves to create shapes capable of grabbing a small object. From there, the tractor beam could be programmed to hold the object or move it around.

"In our device we manipulate objects in mid-air and seemingly defy gravity. Here we individually control dozens of loudspeakers to tell us an optimal solution to generate an acoustic hologram that can manipulate multiple objects in real-time without contact," Sriram Subramanian, professor of informatics at the University of Sussex, said in a statement.

The working tractor beam can be control objects using three different acoustic shapes. The first shape resembles a pair of tweezers that can be used to move the object. The second shape is an acoustic cyclone that pushes the beads into the center of the beam. An acoustic cage, or bottle, can be used to control the object.

Previous to control objects with sound was met with severe limitations as the beam had to be enclosed. Maneuverability was also lacking in the previous iterations of the tractor beam. "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," lead author Asier Marzo, PhD student from the University of Bristol, said in a statement.

Before thoughts of a future where tractor beams are used to move furniture, cars or other large objects, the researchers have a more practical application for the technology. An acoustic tractor beam would be a great way to deliver drugs control mini surgical machines. The research was published in the journal Nature Communications.