Start Date

2016 12:00 AM

Description

In recent years, various types of acoustic metamaterials have been proposed with capabilities for overcoming the diffraction limit. However, typically such developments only consider the acoustic regime [1] or imaging in liquid media [2]. In this paper we demonstrate the application of a holey structured metamaterial lens for sub-wavelength imaging of defects in a metallic sample, in the ultrasonic regime. Finite Element (FE) simulations are used to study longitudinal wave interaction with ideal cracks in isotropic elastic materials. Holey-structured meta-lenses are then used to transmit the scattered waves. We experimentally demonstrate a subwavelength resolution of λ/7 with a sub-wavelength notch in an aluminium block, which to the best of our knowledge this is the highest resolution achieved in the ultrasonic regime.

Language

en

File Format

application/pdf

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Jan 1st, 12:00 AM

Subwavelength Resolution of Cracks in the Metallic Materials

In recent years, various types of acoustic metamaterials have been proposed with capabilities for overcoming the diffraction limit. However, typically such developments only consider the acoustic regime [1] or imaging in liquid media [2]. In this paper we demonstrate the application of a holey structured metamaterial lens for sub-wavelength imaging of defects in a metallic sample, in the ultrasonic regime. Finite Element (FE) simulations are used to study longitudinal wave interaction with ideal cracks in isotropic elastic materials. Holey-structured meta-lenses are then used to transmit the scattered waves. We experimentally demonstrate a subwavelength resolution of λ/7 with a sub-wavelength notch in an aluminium block, which to the best of our knowledge this is the highest resolution achieved in the ultrasonic regime.