The tractor beam works by surrounding the object with high-intensity sound and this creates a force field that keeps the objects in place. At the moment it reliably hoists tiny beads up to 4mm (0.16 inches) wide, but a larger version of the device using the same principle should be able to float a beach ball 30 feet in the air, Marzo said. Researchers say the technology could create a new generation of touch screens made of millions of moving, 3-D pixels.
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However, the sonic tractor beam could be of far more use here on Earth. This is the first time acoustic holograms have been described, according to Marzo, and the first time they’ve been used in this context.
The researchers used an array of 64 miniature loudspeakers to create high-pitch and high-intensity sound waves. By carefully controlling the output of the loudspeakers the object can be either held in place, moved or rotated.
This time, the panel of speakers is flat. The first is an acoustic force field that resembles a pair of fingers or tweezers.
Their technique allows them to create a variety of shapes with the sound, allowing them to manipulate objects in different ways. “We are also exploring how to manipulate thousands of particles individually”.
In Star Trek, the crew of the USS Enterprise use a focused beam of graviton to capture and move passing objects in space.
“When the experiments were not working (for about six months) they were a few of the most dispiriting you could think of”, stated Bruce Drinkwater, a professor of ultrasonics at the University of Bristol.
Previous sound levitation setups, like the one in the video above, surround the particles scientists want to control from at least two sides, like a sandwich.
By tightly orchestrating the release of these sound waves, it should be possible to create a region with low pressure that effectively counteracts gravity, trapping an object in midair. “This potentially enables the manipulation of clots, kidney stones, drug capsules, microsurgical instruments or cells inside our body without any incision”, Marzo said.
Paper: Holographic acoustic elements for manipulation of levitated objects by Asier Marzo, Sue Ann Seah, Bruce W. Drinkwater, Deepak Ranjan Sahoo, Benjamin Long and Sriram Subramanian is published in Nature Communications.
A real-life tractor beam that can invisibly ensnare and levitate objects has been developed by British scientists.
Researchers recently created an acoustic hologram, or a 3D sound field projected onto a 2D space, which can be used as acoustic tweezers, cages and twisters that manipulate objects as they levitate in air. But for the system to be useful for medical operations, the team would need to miniaturize it to manipulate objects on the micron scale.
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“The possibility of holding and manipulating objects from a distance and without physical contact is intrinsically exciting”, Marzo stated in an email.
