Sound waves may not appear to hold much power, but scientists believe directing them in the right way could allow them to hide objects and even levitate them in the air.

Researchers in the US have developed technology to manipulate sound waves on fixed paths around an acoustic ‘bottle’.

The technique could be used to re-route sound waves around an object making them invisible to sonar detection.


“We need to find ways to bend acoustic wave fields without depending on the use of a highly engineered medium,” said Xiang Zhang, director of Berkeley Lab’s Materials Sciences Division. “With our bottle beam technique, we can design and synthesize acoustic bottles that are capable of directing sound waves along paths of desired curvature through homogeneous space without the need of metamaterials or any other highly engineered medium.”

The bottle features a three-dimensional curved shell in which a wall of high acoustic pressure surrounding a null pressure region. Sound waves forming in the bottle are concentrated into a beam that travels down the walls. The waves are created using loud speakers.

The bottle sound waves can open new paths to applications in which there is a need to access hard-to-reach objects hidden behind obstacles, such as acoustic imaging and therapeutic ultrasound.

“These giant acoustic traps could lead to new technologies and devices for a variety of applications in chemistry, materials, as well as biosciences,” said Sui Yang, author of the paper describing the method.

The findings are published in the journal Nature Communications.