The effective operation of certain electronic, medical, industrial, and testing equipment relies on high-quality focusing imaging capability, which also plays a vital role in the field wave physics. Therefore, continuously improving resolution capacity is essential. However, homogeneous medium dominated by diffraction limit, best for could only reach half wavelength corresponding to lowest operating frequency, significantly hindering relevant application value. development phononic crystals...

To break the high additional mass ratio requirement of traditional vibration absorbing materials/devices, and overcome shortcoming narrow operating frequency band conventional local resonance metamaterial dampers, this paper proposes a lightweight multi-scale material/structure integrated elastic for broadband absorption. By replacing components in macroscopic absorber with composite body filled microscopic particle materials, structure/material design between oscillator is realized. The...

Many advanced physical properties can be realized by using well-designed acoustic metamaterial (AM) structures, which have significant application value in engineering. In particular, thin-walled membrane, plate, and shell-type structures with deep subwavelength thicknesses that meet light weight requirements attracted the attention of many researchers engineers from various specialized fields. This Tutorial systematically introduced structural design methods, acoustic/elastic wave...

We propose a multi-order Helmholtz metamaterial with deep-subwavelength thickness in which perfect continuous acoustic absorption is achieved within 400 Hz ∼ 2800 Hz. The composed of multiple detuned cells, each constructed by several perforated plates inserting into the cavity resonator (HR) and hence gains individually-tuned high-order peaks besides original HR peak. By precisely designing peak extra-broadband can be obtained. This kind metamaterials could possess broad applications noise...

A space-shift phase-coherent cancellation acoustic metasurface is developed, which can achieve broadband low-frequency sound absorption via ultra-thin integrated structure composed of multiple units with weak capability. Through a design the channel length, large-size required in thickness direction for transferred into an extremely space layer. The gradient length are compactly arranged layer through folding, coplanar component working bandwidth exceeding octave and only λ/25 to λ/57...

This paper proposes a purely flexible lightweight membrane-type acoustic structure, wherein one kind of rubber material takes the roles mass and stiffness another type EVA (ethylene–vinyl acetate copolymer) or plastic functions as localized for each unit. Because both scatterers base are constituted by same material, this structure breaks limitation that metamaterials phononic crystals need different materials with relatively large density elasticity modulus ratios to play respectively....

In this paper, we propose a general design concept for acoustic metamaterials that introduces ubiquitous synergetic behavior into the procedure, in which structure of is driven by its functional requirements. Since physical properties widely used, resonant-type are mainly determined eigenmodes structure, first introduce through modal displacement distributions on two typical plate-type structures. Next, employing broadband sound attenuations involve both insulation and absorption as targets,...

The experimental realization and theoretical understanding of a two-dimensional multiple cells lumped ultrathin lightweight plate-type acoustic metamaterials structures have been presented, wherein broadband excellent sound attenuation ability at low frequencies is realized by employing element coupling resonant effect. basic unit cell the consists an stiff nylon plate clamped two elastic ethylene-vinyl acetate copolymer or acrylonitrile butadiene styrene frames. strong (up to nearly 99%)...

The diffraction limit restricts the smallest diameter of a wave's focal spot in homogeneous medium to no less than half operating wavelength.

In this paper, we propose a bilayer plate-type lightweight double negative metasurface based on new synergetic coupling design concept, by which the perfect absorption, bands, free manipulation of phase shifts with 2π span and acoustic cloak can be successively realized. Firstly, behavior between resonant anti-resonant plates is presented to construct unit in each component respectively provides pre-defined function realizing absorption. Based structure, band simultaneously effective mass...

This paper proposed a metamaterial design method that uses soft matter for constructing unique acoustic boundary to effectively improve broadband sound absorption performance. Specifically, attaching flexible polyvinyl chloride (PVC) gel layer with an elastic modulus as low few kilopascals and thickness of millimeters the inner wall cavity-type sound-absorbing structure significantly improved performance composite in low-frequency ranges. The enhancement mechanism differed from those...

We present an ultra-broadband acoustic metamaterial with inhomogeneous high-order Fabry–Pérot (FP) resonances that achieves near-perfect continuous absorption in the range of 400–10000 Hz. The unit is composed multiple FP channels cross-sectional areas, allowing for flexible adjustment impedance characteristics each channel. This approach prevents peaks’ resistances from increasing rapidly and ensures a smooth resistance characteristic across broad frequency range. As result, performance...

Abstract To address the incompatibility between high environmental adaptability and deep subwavelength characteristics in conventional local resonance metamaterials, overcome deficiencies stability of existing active control techniques for band gaps, this paper proposes a design method pure metal vibration damping metamaterial with continuously tunable stiffness wideband elastic wave absorption. We dual-helix narrow-slit unit, which possesses triple advantage spatial compactness, low...