#phononic

The phononic devices include parts that vibrate extremely fast, moving back and forth up to tens of millions of times per second. The team developed these devices by creating silicon nitride drums that are just 90 nanometers thick. (A human hair is about a thousand times thicker.) The drums are arranged into grids, with different grid patterns having different properties.

Daraio, along with former Caltech postdoctoral scholar Jinwoong Cha showed that arrays of these drums can act as tunable filters for signals of different frequencies. They also showed that the devices can act like one-way valves for high-frequency waves. The ability to transmit waves in only one direction helps keep the signal stronger by reducing interference.

Find out more:

http://www.caltech.edu/news/microscopic-devices-control-vibrations-could-allow-smaller-mobile-devices-84641