The researchers were able to accomplish this feat by building a grid comprising 64 loud speakers. The sound they emit is beyond human hearing, and the output can be adjusted to change the type of field created by the sound to hold the object, contain it, or pull it.
In the video below, the researchers demonstrate how objects can be moved around by an invisible hand that holds the object between two fields, like the object is being pinched and moved. In another, researchers showed it could pull an object one way using a twister-like cyclone, much like a tractor beam.
“We have in mind cells and drug-holding micro-capsules,” professor Bruce Drinkwater stated in an email to Discovery. “If we could manipulate these within the body, e.g., to deliver drugs to tumors, this would be hugely important.”
Past tractor beams have demonstrated the possibility of using light to push and pull objects. Bill Nye (the science guy) explains that’s because “light, even though it has no mass, has a tiny, tiny bit of momentum. Just while you’re sitting there in a room with the lights on and when you’re out in the sun, there’s just a tiny, tiny push on you because it’s pure energy.”