Spider Web-Inspired Lightweight Membrane-Type Acoustic Metamaterials for Broadband Low-Frequency Sound Isolation

Abstract

Membrane-type acoustic metamaterial (MAM) has exhibited superior sound isolation properties, as well as thin and light characteristics. However, the anti-resonance modes of traditional MAMs are generated intermittently in a wide frequency range causing discontinuities in the anti-resonance modes. Achieving broadband low-frequency sound attenuation with lightweight MAM design is still a pivotal research aspect. Here, we present a strategy to realize wide sound-attenuation bands in low frequency range by introducing the design concept of bionic configuration philosophy into the MAM structures. Built by a polymeric membrane and a set of resonators, two kinds of MAM models are proposed based on the insight of a spider web topology. The sound attenuation performance and physical mechanisms are numerically and experimentally investigated. Multi-state anti-resonance modes, induced by the coupling of the bio-inspired arrangement and the host polymer film, are systematically explored. Significant sound attenuation is numerically and experimentally observed in both the lightweight bio-inspired designs. Remarkably, compared with a traditional MAM configuration, a prominent enhancement in both attenuation bandwidth and weight-reduction performance is verified. In particular, the bio-inspired MAM Model I exhibits a similar isolation performance as the reference model, but the weight is reduced by nearly half. The bio-inspired Model II broadens the sound attenuation bandwidth greatly; meanwhile, it retains a lighter weight design. The proposed bio-inspired strategies provide potential ways for designing sound isolation devices with both high functional and lightweight performance.

Optimized structures for vibration attenuation and sound control in nature: A review

“…131 The possibility of designing lowfrequency sound attenuators is also regarded as a common objective in metamaterials design, and spiderweb-inspired structures seem to be able to provide lightweight solutions to achieve this goal. 132,133 Spider sensing Although many spiders have poor sight, remarkable sensors that make them capable of interacting with their surroundings have evolved, 105 including hair-shaped air movement detectors, tactile sensors, and thousands of extremely efficient strain detectors (lyriform organs such as slit sensilla) capable of transducing mechanical loads into nervous signals embedded in their exoskeletons. [134][135][136] Air flow sensors, named trichobothria (Figure 5D), seem to be specifically designed to perceive small air fluctuations induced by flying prey, which are detectableat a distance ofseveral centimetres.…”

Acoustic Insulation Characteristics and Optimal Design of Membrane-Type Metamaterials Loaded with Asymmetric Mass Blocks

“…Chen et al [ 26 ] proposed a new acoustic metamaterial comprised of two membranes and two ring masses which can effectively broaden the sound attenuation zone. Huang et al [ 27 ] proposed two kinds of MAMs built by a polymeric membrane and a set of resonators based on the concept of bionic configuration philosophy, and this design greatly broadens the sound attenuation bandwidth in the lightweight condition. At present, most scholars select symmetric structures for the design of mass blocks, such as circle, ring, or symmetric distribution, which make the entire coupling system maintain a symmetric vibration behavior.…”

Prey Impact Localization Enabled by Material and Structural Interaction in Spider Orb Webs

“…[ 3,4 ] Spider orb webs are the product of evolutionary adaptation, and are able to deliver a compromise between different requirements, such as absorbing the impacts of prey while also efficiently transmitting information about the nature and position of vibration sources, [ 5 ] which the spider uses in addition to visual and olfactory information. Spider orb webs have proven to be one of the most inspiring systems to design novel structures able to manipulate elastic waves, [ 6–9 ] which further encourages the investigation of their complex mechanics.…”