Holey-structured tungsten metamaterials for broadband ultrasonic sub-wavelength imaging in water

Metamaterials exhibiting Fabry-Perot resonances are shown to achieve ultrasonic imaging of a sub-wavelength aperture in water immersion across a broad bandwidth. Holey-structured metamaterials of different thickness were additively manufactured using a tungsten substrate and selective laser melting, tungsten being chosen so as to create a significant acoustic impedance mismatch with water. Both broadband metamaterial behavior and sub-wavelength imaging in water are demonstrated experimentally and validated with finite element simulations over the 200-300 kHz range.

Automated summary

Experiments and finite element simulations demonstrate the ability of metamaterials to achieve sub-wavelength ultrasonic imaging of an aperture in water immersion across a broad bandwidth. The use of tungsten in holey-structured metamaterials creates a significant acoustic impedance mismatch with water, enabling the broadband metamaterial behavior.