A type of metamaterial device that allows better water-to-air sound transmission
January 29, 2018 by Bob Yirka, Phys.org report
A team of researchers from Yonsei University in Korea and Hokkaido University in Japan, has developed a metamaterial device that allows for much better than normal sound transfer between water and air. In their paper published in Physical Review Letters, the researchers describe their device, how it works and the ways it needs to be improved.
Normally, it is nearly impossible to hear underwater sound from the air above—the same is true in reverse. This is because of acoustic impedance forming a sound barrier. Sound waves bounce off the barrier, preventing them from escaping. In this new effort, the researchers applied a metamaterial device (a metasurface) to the barrier that essentially serves as a tunnel between the water and the air, allowing more sound waves to pass through.
Read more at:
https://phys.org/news/2018-01-metamaterial-device-water-to-air-transmission.html#jCp
