3D‐Printed Lattice Structures for Sound Absorption: Current Progress, Mechanisms and Models, Structural‐Property Relationships, and Future Outlook

Abstract

The reduction of noises, achieved through absorption, is of paramount importance to the well‐being of both humans and machines. Lattice structures, defined as architectured porous solids arranged in repeating patterns, are emerging as advanced sound‐absorbing materials. Their immense design freedom allows for customizable pore morphology and interconnectivity, enabling the design of specific absorption properties. Thus far, the sound absorption performance of various types of lattice structures are studied and they demonstrated favorable properties compared to conventional materials. Herein, this review gives a thorough overview on the current research status, and characterizations for lattice structures in terms of acoustics is proposed. Till date, there are four main sound absorption mechanisms associated with lattice structures. Despite their complexity, lattice structures can be accurately modelled using acoustical impedance models that focus on critical acoustical geometries. Four defining features: morphology, relative density, cell size, and number of cells, have significant influences on the acoustical geometries and hence sound wave dissipation within the lattice. Drawing upon their structural‐property relationships, a classification of lattice structures into three distinct types in terms of acoustics is proposed. It is proposed that future attentions can be placed on new design concepts, advanced materials selections, and multifunctionalities.

Lattice Architectures for Thermoelectric Energy Harvesting

“…45 Under compression, the honeycomb and strut-based lattices display anisotropic properties, with the strut-based lattice being prone to plastic buckling and strain localization. With the elimination of joints in surface-based lattices and thus minimization of stress concentration points, 29 they possess higher resistance against compressive deformations as compared to strut-based lattices. However, surface-based lattices such as gyroids may require longer slicing times for 3D printing due to the complexity of the interlocking channels.…”

“…Other forms of bioinspired lattices such as honeycombs and nacre can also give rise to re-entrant honeycomb metamaterials or nacre-like composite metamaterials . These lattice structures create opportunities for lightweight, high-energy absorption, high-strength, and sound absorption engineered materials. − These metamaterials serve to increase the mechanical characteristics of engineered tools and have been reviewed by several groups. − …”

“…Mechanical parameters (e.g., fracture toughness, hardness, Young’s modulus, and compressive strength) for bulk thermoelectric legs as well as strengthening strategies have been reported and consolidated. , Besides these material properties, physical properties such as macro design play a role in the overall mechanical properties. While all three lattice structures present some degree of vibration attenuation due to their high specific stiffness, it is particularly impressive in the honeycomb and surface-based lattices because of the mechanisms present to dissipate energy , and the structural design resulting in a low natural frequency, respectively . Under compression, the honeycomb and strut-based lattices display anisotropic properties, with the strut-based lattice being prone to plastic buckling and strain localization.…”