Abstract
We present the first experimental demonstration of focusing ultrasound waves through a flat acoustic metamaterial lens composed of a planar network of subwavelength Helmholtz resonators. We observed a tight focus of half-wavelength in width at 60.5 kHz by imaging a point source. This result is in excellent agreement with the numerical simulation by transmission line model in which we derived the effective mass density and compressibility. This metamaterial lens also displays variable focal length at different frequencies. Our experiment shows the promise of designing compact and lightweight ultrasound imaging elements.
- Received 26 March 2009
DOI:https://doi.org/10.1103/PhysRevLett.102.194301
©2009 American Physical Society
Synopsis
Metamaterial brings sound into focus
Published 18 May 2009
A compact lens made from an acoustic metamaterial can focus ultrasonic waves to half a wavelength.
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