Fig. 3: Design of the acoustic absorber.
From: Magnetic–acoustic biphysical invisible coats for underwater objects
a Schematic of the biphysical invisible coat design. From top to bottom, it consists of an AMS layer, FM layer, and rigid brass ground layer. The AMS layer is made of a PDMS elastic sheet periodically doped with air-hole cavities. b The reflectivity (R), transmissivity (T), and absorptivity (A) spectra of an optimized absorber with parameters D = H = 150 μm, p = 2.3 mm, d = 255 μm, and t1 = 1.05 mm. The solid lines denote the analytical results, and the symbols denote the simulation results. The inset draws the acoustic displacement in PDMS, and pressure in water and air cavity patterns at normal incidence. c The same scattering parameters for the sample as a function of the incident angle at 100 kHz. d–f The angle- and frequency-dependent scattering parameters R, T, and A for the same sample.
