Led by mechanical science and engineering professor Nicholas Fang, Illinois researchers have demonstrated an acoustic cloak, a technology that renders underwater objects invisible to sonar and other ultrasound waves.
"We are not talking about science fiction. We are talking about controlling sound waves by bending and twisting them in a designer space," said Fang, who also is affiliated with the Beckman Institute for Advanced Science and Technology.
The researchers tested their cloak's ability to hide a steel cylinder. They submerged the cylinder in a tank with an ultrasound source on one side and a sensor array on the other, then placed the cylinder inside the cloak and watched it disappear from their sonar.
"The structure of what you're trying to hide doesn't matter," Fang said. "The effect is similar. After we placed the cloaked structure around the object we wanted to hide, the scattering or shadow effect was greatly reduced."
I'm sure the Navy will have kittens if this becomes practical. What's to protect the coast or carrier battle groups from enemy subs?