Article
Materials Science, Multidisciplinary
Jiaying Wang, Florian Allein, Cecile Floer, Nicholas Boechler, James Friend, Oscar Vazquez-Mena
Summary: This study presents a novel technology to fabricate acoustic metamaterials in water using microstructured silicon chips, enabling their operation in the MHz range for applications in biomedical ultrasound. The metamaterials are formed by assembling silicon chip unit cells that incorporate silicon nitride membranes and Helmholtz resonators. Finite-element method simulations and experimental measurements confirm the negative-index behavior of the material in the 0.25-0.35 MHz range. This work opens up new possibilities for achieving relevant frequencies for biomedical ultrasound applications using silicon technology microfabrication.
ADVANCED MATERIALS TECHNOLOGIES
(2022)
Article
Mechanics
Mingming Chen, Minghui Fu, Lingling Hu
Summary: This paper presents the design of a novel metamaterial with multiple load-bearing modes, exhibiting peculiar properties under tension and compression. The material allows adjustment of the ratio of tensile elastic modulus to compressive elastic modulus and features an asymmetric stiffness matrix, breaking the classical model of symmetric stiffness matrix for conventional materials. The material is expected to have applications in various fields.
COMPOSITE STRUCTURES
(2021)
Article
Engineering, Mechanical
Amin Montazeri, Ehsan Bahmanpour, Majid Safarabadi
Summary: An innovative mechanical metamaterial with sign-switching stiffness-changing properties and potential applications in the automotive and construction industries is presented in this study. The metamaterial, designed by modifying and combining hexagonal and re-entrant unit cells, is fabricated using additive manufacturing and explored through experiments and finite element analysis. The parametric studies show that the auxeticity and Poisson's ratio sign-changing properties of the material can be tuned by modifying the design parameters. Additionally, the load-carrying capacity and stiffness-changing properties can be adjusted by modifying the unit cell parameters.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
Yafeng Bi, Ping Zhou, Han Jia, Fan Lu, Yuzhen Yang, Yimeng Zhang, Peng Zhang, Jun Yang
Summary: Adjusting the variation of hollow regular polygons can achieve independent manipulation of mass density and bulk modulus underwater, thus manipulating the propagation of sound wave. By designing and using metafluids with the same impedance but different sound velocities, underwater impedance-matched gradient index lenses can be realized. Additionally, combining the proposed metafluid with other artificial structures can achieve acoustic parameters with great anisotropy, exemplified by the design and demonstration of an impedance-matched underwater acoustic carpet cloak.
MATERIALS & DESIGN
(2023)
Article
Engineering, Mechanical
Jun-Young Jang, Choon-Su Park, Kyungjun Song
Summary: According to the mass law, dense and thick materials are typically used for blocking low-frequency sound waves. However, this study introduces the use of lightweight and thin metamaterials for effective soundproofing. The proposed soundproofing consists of a thin membrane combined with an ultralight membrane-type acoustic metamaterial. Through vibration in the membrane, the soundproofing can be easily tuned to achieve broadband sound insulation. The results of numerical and experimental tests demonstrate the excellent sound-blocking characteristics of this soundproofing material, making it suitable for applications in noise insulation, such as acoustic enclosures, automobile insulation, walls, and engine rooms.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Acoustics
Junyi Liu, Wenkai Dong, Ting Wang, Meixia Chen, Youmin Lu
Summary: Currently, there is a growing concern about noise pollution in ducts, and studies on sound absorption in pipes are being conducted globally. In order to tackle the issue of eliminating low-frequency noise in pipelines, a multi-resonant cavity duct metamaterial is proposed. The acoustic properties of the metamaterial are calculated using the energy method based on the Hamilton principle and the transfer matrix methodology. The results show that the duct metamaterial, with its band gaps and negative bulk modulus, achieves multiple sound absorption peaks and is beneficial for eliminating low-frequency sound. The plate-cavity interaction contributes to the excellent acoustic characteristics of the duct metamaterial for sound insulation. Parametric analysis of the proposed structure is also conducted. This study demonstrates the potential application of duct metamaterials for multi-frequency sound absorption in engineering practice.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Engineering, Environmental
Ved Prakash Ranjan, Sudha Goel
Summary: The study found that polypropylene exposed to different environmental conditions undergoes significant physical, chemical, and mechanical changes when influenced by UV radiation. Samples exposed to air suffered the most severe damage, while samples exposed to saline water showed resistance to mechanical changes.
RESOURCES CONSERVATION AND RECYCLING
(2021)
Article
Materials Science, Multidisciplinary
Limei Hao, Yujia Li, Xiaole Yan, Xiao Yang, Xueyi Guo, You Xie, Shaofang Pang, Zhi Chen, Weiren Zhu
Summary: Tri-band negative modulus acoustic metamaterials with flexible operation characteristics can be designed by changing the hole sizes of nested split hollow spheres. The proposed metamaterial can be easily extended to multiple operation bands and coupled with negative mass density structures for constructing multi-band double-negative metamaterials.
FRONTIERS IN MATERIALS
(2022)
Article
Physics, Applied
M. Mallejac, A. Merkel, J. Sanchez-Dehesa, J. Christensen, V. Tournat, V. Romero-Garcia, J. -P. Groby
Summary: This paper investigates the feasibility of cloaking obstacles using Plate-type Acoustic Metamaterials (PAMs) and presents two distinct strategies for achieving hiding configuration. The study focuses on dealing with unavoidable losses in the system and reports on the analytical, numerical, and experimental findings of a hiding zone. The comparison between cloaking and hiding configurations highlights the difference in scattering properties and the impact of obstacles on the hiding device.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Junyu Li, Xiaowen Wu, Chenlin Wang, Qibai Huang
Summary: This paper proposes a four-vibrator acoustic metamaterial structure with phononic crystals, aiming to broaden the sound insulation performance at medium and high frequencies while retaining the advantages of sound insulation at low frequencies. The sound insulation performance and characteristics of the structure are analyzed using a semi-analytical method and an equivalent medium method, and its performance in a cylindrical state is verified through finite element simulation.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
V Harinarayana, Y. C. Shin
Summary: In this study, a comprehensive design and fabrication of a three-dimensional axisymmetric auxetic structure that exhibits uniform and axisymmetric transverse deformation under longitudinal compression loading is proposed. The design of the metamaterial is generated by revolving a two-dimensional parabolic curve along the axis of rotation and subsequently perforating the structure periodically with elliptical voids. The significance of the perforations is elucidated by comparing the metamaterial structure to a plain structure.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Multidisciplinary
Tinggui Chen, Junrui Jiao, Dejie Yu
Summary: The study proposes a method based on the gradient acoustic-grating metamaterial (GAGM) for detecting harmonic and periodic impulse signals more easily. Numerical and experimental investigations demonstrate that GAGM achieves acoustic rainbow trapping to spatially separate different frequency components. This work opens up new vistas for weak signals detection in various areas.
Article
Physics, Applied
Zi-xiang Xu, Hai-yang Meng, An Chen, Jing Yang, Bin Liang, Jian-chun Cheng
Summary: A tunable low-frequency acoustic absorber composed of multi-layered ring-shaped microslit tubes with subwavelength thickness is proposed and experimentally verified, achieving high-efficient acoustic absorption and superior impedance manipulation capability. The proposed metastructure allows continuous tunability over a wide working frequency band and shows potential for practical engineering applications such as noise control.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Mechanical
Lumin Shen, Kai Wei, Ke Yuan, Chong Shi, Zhendong Li, Zhonggang Wang
Summary: This work proposes a novel metamaterial that combines auxeticity and thermal shrinkage by introducing a bi-material double-square into the star-shaped configuration. The results show that the desired properties of the metamaterial can be customized by adjusting the appropriate geometric and material parameters. Compared with other star-shaped metamaterials, the design in this study exhibits significant advantages in auxeticity and thermal shrinkage, and it also maintains auxetic properties under large deformation. This metamaterial has potential applications in smart actuators and satellite antennas due to its thermal stability.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Chemistry, Physical
Kejing Ma, Ting Tan, Zhimiao Yan, Fengrui Liu, Wei-Hsin Liao, Wenming Zhang
Summary: A novel metamaterial and Helmholtz coupled resonator (MHCR) are proposed in this paper to enhance sound energy density through energy focusing and pressure amplification, with promising results in increasing the transmission ratio and voltage output of energy harvesters.
