The U.S. research team used sound waves to levitate polyethylene particles of around 1mm in diameter to see how they interact with each other in 2D in groups of six or seven.
In the perhaps not so distant future, surgeons could perform a range of medical procedures all without touching the patient, thanks to advancements in 'acoustic tweezers'.
UK researchers have become the first in the world to develop technology which can bend sound waves around an obstacle and levitate an object above it.
The world's most powerful acoustic tractor beam could enable the manipulation of drug capsules or micro-surgical implements within the body. The discovery could even lead to levitating humans.
