Environmental
4D Printing with Liquid Crystal Elastomers: Materials, Methods, and Emerging Applications
A review summarizes how 4D printing of liquid crystal elastomers enables programmable, reversible shape changes and surveys fabrication methods, integrations, and remaining challenges.
Incorporating extended neck Helmholtz resonators into an advanced multi-degree of freedom acoustic metamaterial for low-frequency, broadband acoustic absorption
An advanced multi-degree-of-freedom acoustic metamaterial is designed by incorporating extended neck Helmholtz resonators to target low-frequency, broadband sound absorption.
Acoustic metamaterial in low-frequency underwater noise mitigation
A lightweight, 3-D-printed acoustic metamaterial is proposed and lab-tested to attenuate wide-band low-frequency underwater noise via sound insulation.
Design and development of one-dimensional acoustic bundle ventilated metamaterial
A one-dimensional kink-fiber acoustic meta-structured blanket is proposed and validated to enable broadband sound absorption while permitting airflow through the structure.
Metamaterial acoustic barriers for traffic noise control in urban zones
Geometrically periodic acoustic metamaterial barriers, tested at 1:10 scale, can reduce traffic noise, with porous polyethylene layers improving absorption over a wide frequency range.
Duct Metamaterial Muffler with Composite Acoustic Porous Media: Acoustic Optimization via Periodic Arrangement, Particle Swarm Optimization and Experimental Validation
A composite acoustic porous duct metamaterial muffler with periodic tortuous channels and optimized porous layers achieves improved broadband transmission loss validated by experiments.
Active-Learning-Guided Acoustic Metamaterial Resonators for Low-Frequency Noise Suppression and Piezoelectric Energy Harvesting
Active-learning-guided inverse design enables scalable acoustic metamaterial resonators that suppress low-frequency noise and harvest acoustic energy using integrated piezoelectric stacks.
Thin Acoustic-Composite Structures With Metamaterial Inclusions for Enhanced Low-Frequency Sound Absorption
Thin porous acoustic composites with tunable labyrinthine metamaterial inclusions achieve enhanced low-frequency absorption via multiresonant behavior confirmed by acoustic tests.
Inverse design of acoustic metamaterial sound barriers for road traffic noise control
An inverse-design framework links measured road-noise spectra to optimized nested-Helmholtz acoustic metamaterial unit cells, yielding broader bandgap attenuation confirmed by impedance-tube tests and field trials.
The role of seismic metamaterials on soil dynamics
It presents a time-modulated seismic metamaterial concept for structured soils, linked to in-situ seismic lens observations and potential energy harvesting and analogous computation using ambient seismic noise.
A data-driven framework for predicting the acoustic performance of metamaterial arrays
A data-driven framework combines unit-level surrogate models with limited full-array simulations to efficiently predict array-level acoustic transmission loss for complex metamaterial panels.
Emergence of Seismic Metamaterials: Current State and Future Perspectives
The article surveys seismic metamaterials in soils and outlines what effective-medium theory suggests about achievable material parameters and future large-scale auxetic designs.