Acoustic Metamaterials
Sub-wavelength focusing of acoustic waves in bubbly media
We derive a point-scatterer approximation for the acoustic pressure field due to scattering from a large number of acoustic bubbles in a liquid in the low frequency regime. We use this approximation as a basis for a time-reversal simulation of sub-wavelength focusing. Our results indicate that sub-wavelength focusing is achievable when the excitation frequency is slightly below the Minnaert resonance frequency of a single bubble.
By Dr. Brian Fitzpatrick
