Cloaking Device: Not Just for Sy-Fy Anymore

From the pages of a Sy-fy novel, scientists have created an acoustic underwater invisibility cloaking device.

The new tech scatters sound waves around an object, making it undetectable by sonar.

The creators of this device outlined their work at a scientific meeting in Minneapolis. This technology is possible by the use of so-called “smart” materials that hold unique properties.

When ships send out signals to locate objects in the ocean or to create a map for the sea floor, the signal bounces back to its source. With this cloaking device, it appears as though the object isn’t there.

Amanda Hanford and her team from Pennsylvania State University created a three-foot-tall pyramid out of perforated steel plates. This creation would be able to cloak objects from sonar detection.

To test the device, they placed the structure in a tank and directed sound waves towards it. The waves were between 7,000 and 12,000 kHz, and multiple receivers were set up to record the reflected waves.

The waves returned from the metamaterial turned out to be in the same phase as those waves reflected from the bottom of the tank where it sat.

Possibilities with A Cloaking Devicei

Waves have both peaks and valleys. When in the same phase, the heights of the waves synchronize with one another. This uniformity makes the object invisible from detection instruments.

Although the idea seems preposterous in reality, Dr. Hanford says that the math is showing that this is very much a possible reality. They are now looking into what is possible to create with these materials.

Before, some research looked into the possibility of creating meta-materials which would hide objects in the air. However, added factors of water take it one step further. Because water is denser than air, it makes it more difficult to compress.

This technology could potentially have real-world applications. The materials could dampen sound, so they are not visible underwater.

Sonar,  or: SOund Navigation And Ranging, is a method used to detect underwater objects or to map the seafloor. Sound waves emit from a source and reflect off their surroundings, returning to its source with a type of map of the area. This technology allows for communication or deterring from other objects. Both bats and dolphins use this as a way of viewing and interpreting the world around them.