Sonic Tractor Beam Can Levitate And Manipulate Objects – High-Amplitude Sound Waves Create Controllable Holograms In Air [Video]

A sonic tractor beam that uses high amplitude sound waves to levitate and manipulate objects in mid-air has been built.

Researchers at the Universities of Sussex and Bristol have successfully built a sonic tractor beam using an array of miniature speakers that can precisely control small objects, without the need to touch them. Though the ability of the tractor beam is limited to moving objects with maximum 5mm diameter, the sound waves are so precisely controlled that the engineers hope the technology will allow creation of sound-based assembly lines that rely only on the acoustic manipulation to move and fit objects. However, the more immediate aim of the team is to help doctors manipulate drugs into a patient’s body without the need for invasive surgery.

In a paper published in Nature Communications, simply titled “Holographic Acoustic Elements For Manipulation of Levitated Objects,” researchers explained how they figured out a way to precisely manipulate tiny objects using what they prefer to call acoustic holograms. The researchers used forces generated and maintained by a field of ultrasonic waves to control lightweight, 5mm-sized polystyrene beads in the air. The team assures that their sonic tractor beam can control matter irrespective of the material. In other words, the system is limited by the size of the object, and not by what the object is made of.

The technology uses an array of 64 miniature loudspeakers to produce a range of high-pitch and high-intensity sound waves, reported IGN. This grid of tiny loudspeakers then generate a sonic tractor beam that can levitate, hold, and otherwise manipulate a tiny object that appears as if it is suspended in mid-air.

In reality, the ultrasonic sound waves are able to create a field in which the matter remains trapped. Hence the term “hologram,” as the researchers have been able to transform sound into a 3D force field. By carefully managing the intersecting sound waves, the team was able to create three different moving acoustic holograms that acted like tractor beams, which was then manipulated to move the move that was trapped within the acoustic hologram.

The researchers were able to create tweezer-like twin traps for vertical movement, twister-like vortex traps for circular movement, and bottle-shaped traps. When working in conjunction, these acoustic holograms act like a sonic tractor beam which can levitate, grab, nudge, and spin the particles. Speaking about the same, Bruce Drinkwater, Professor of Ultrasonics in the University of Bristol’s Department of Mechanical Engineering, said as follows.

“My colleagues also tried a novel sci-fi analogy to test the invisible manipulation. We wanted to demonstrate that we could do it upside down. We had a discussion and we thought that everyone thinks of a tractor beam as people being sucked up into space. So we mounted the array upside-down in a cardboard UFO, and the particle gets sucked up into it.”

The researchers envision one day their tractor sonic beam could be used as a sound-based production line to transport delicate objects and assemble them without physical contact, read the statement from the university. However, the researchers also believe that their system can be quite useful in medical field since sound waves can pass through body tissue, said Asier Marzo, a Bristol doctorate student and the lead author of the study.

“It could be used to manipulate kidney stones, clots, or microsurgical instruments that you control from outside, without having to make any incisions in the patient. Or you could hold a drug wherever you wanted to inside a patient, so it doesn’t go anywhere else in the body.”

Sound waves can manipulate objects through air, water, and tissue, greatly expanding the application of the sonic tractor beam, reported the Guardian.

[Photo by YouTube Screen Grab]