Fig. 3: Design and fabrication of SML under cylindrical coordinate system.
From: Soft Metalens for Broadband Ultrasonic Focusing through Aberration Layers
A Illustration of the designed SML applied in a human brain phantom by dispersing tungsten microparticles with silicone elastomer matrix and the SEM imaging at 100 μm and 300 μm scale, respectively. B Tested and theoretical acoustic refractive indices to weight percentage. Photograph in (B) represents sample preparation for SEM. C Schematic diagram of discrete layers distributions and the fabricated SML with seven descrete layers along radial direction. The image of the upper right region is the mixed SML under the weight percentage of 67.8%. D Measured sound speed and density distributions of SML compared with holographic phase by acoustic hologram based on the reciprocity principle.
