Ultrasound wave propagation in time-varying phononic crystals

Phononic crystals demonstrate remarkable effects, but are static and unchangeable. We wish to use dynamic materials as the scatterers within phononic crystals as a means of controlling their properties. We have extended existing static phononic crystal theory to handle time-varying material parameters. The new method provides a closed-form solution to acoustic wave transmission through 1D dynamic phononic crystals. Band gap properties can be significantly altered using time-varying material parameters as the driving mechanism.