New metasurface model shows potential to control acoustic wave reflection

Typically, when a soundwave strikes a surface, it reflects back at the same fundamental frequency with a different amplitude. A new model shows that when a sound wave hits a nonlinear elastic metasurface, the incident fundamental frequency does not bounce back. Instead, the metasurface converts that energy into the wave's second harmonic resonance. Developing this metasurface could help architects reduce noise from performance halls to cityscapes.