A new acoustic invisibility cloak made of a plastic metamaterial makes objects invisible to sound waves, researchers say. It could be used to shield ships from sonar, or build better soundproof walls for concert halls and other spaces. We’ve seen this idea before, but now Duke University researchers have actually built it.
Winter brings the noise of clanking heaters, and other racket and yawp. But a class of experimental materials may lower the decibel level.
By Trevor Thieme
Posted 01.23.2002 at 7:06 pm 2 Comments
Winter brings the noise of cooped-up kids, clanking heaters, and other racket and yawp. But Robert Fricke of the consulting firm Arthur D. Little is trying to lower the decibel level with Lodengraf (Low Density Granular Fill), a class of experimental materials that use granular mixes, such as volcanic glass and nylon flock, to dampen noise.
Five amazing, clean technologies that will set us free, in this month's energy-focused issue. Also: how to build a better bomb detector, the robotic toys that are raising your children, a human catapult, the world's smallest arcade, and much more.