This new material acts like a giant mute button

Smithsonian (April 2) -- Next time you’re in a restaurant or an office or the airport, look up at the ceiling. You might see cloud-like circular panels, or ribbed foam tiles or minimalist wooden slats or hanging banners that look like sails, or just the ubiquitous greyish rectangles of every high school cafeteria in America. Though they may be aesthetically pleasing (or not), these materials are actually designed to absorb sound and make the room quieter. The donut-shaped design of the material is potentially “very useful,” says Kathryn Matlack, a professor of mechanical science and engineering at the University of Illinois at Urbana-Champaign, who studies acoustic metamaterials, since “most sound attenuating materials are solid and prevent airflow.”