“In Case of Fire Break Glass.” The instructions are simple enough to follow when they apply to a fire alarm, especially when there is a tiny hammer attached to the alarm box. But victims trapped inside burning buildings or totaled cars would have a much harder time shattering a full-size window to make their escape. Giuseppe Longobardi, a researcher at IBM in Castellammare di Stabia, Italy, recently patented a device that would allow a disaster victim to press a button on a remote control and safely shatter a window several feet away, or engineers could install a sensor to the window that would make it break automatically in case of smoke or extreme heat.
Longobardi’s invention exploits the same phenomenon that makes a wineglass ring when you rub its rim: resonance. A small resonator placed in a window pane creates acoustical or mechanical vibrations at just the right frequency to make the glass shatter. “The energy in the window builds up until the glass breaks,” Longobardi says. During the manufacturing process, technicians could embed so-called frequency channels within the glass that would direct the vibrations to certain break points. In this way, instead of shattering randomly and creating numerous shards and jagged edges, the glass would break into “harmless little cubes,” Longobardi says. Film studios could also use the technology for special effects.