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Chain of Compressed Spheres

Chain of compressed spheres with amplitude of vibrations shown by the height of the peaks


The nonlinearity and asymmetry present in this chain of compressed spheres can transform vibrations of one frequency, applied at one end of the chain, to vibrations with broadband frequency content leading to rectification. The amplitude of the vibrations is shown by the height of the peaks.

Although places like recording studios and hotel rooms can be built with materials that absorb or reflect sound, mechanisms that truly control the direction of sound waves are still in their infancy. However, researchers at the California Institute of Technology created the first tunable acoustic diode, a device that allows acoustic information to travel only in one direction, at controllable frequencies. The new mechanism brings the idea of true soundproofing closer to reality.

This research was supported by the National Science Foundation, the Office of Naval Research and the A. S. Onassis Benefit Foundation. To learn more, see the Caltech news story Caltech Engineers Develop One-way Transmission System for Sound Waves. (Date of Image: 2011)

Credit: Georgios Theocharis/Caltech

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