Using ultrasound to create a tractor beam
Sound is a mechanical wave. Using an array of 64 miniature loudspeakers, researchers were able to focus these waves and create a force field which can hold an object in place, levitate it, move it or rotate it. Hence the name sonic tractor beam. This is probably not what the Enterprise in Start Trek used (there is no sound in space), but it certainly could be something Darth Vader has hidden up his sleeve.
The discovery was published in Nature Communications and could have a wide range of applications. One example could involve levitating and transport delicate objects or even assembling them, all without physical contact or contamination. On the other hand, a miniature version could grip and transport drug capsules or microsurgical instruments through living tissue.
“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.” – Dr Asier Marzo, the lead author of the paper.
“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.” – Bruce Drinkwater, Professor of Ultrasonics in the University of Bristol’s Department of Mechanical Engineering.
“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 and co-founder of Ultrahaptics.
Marzo, Asier, et al. “Holographic acoustic elements for manipulation of levitated objects.” Nature Communications, 6, (2015)