Article
Acoustics
Srajan Dalela, Balaji Ps, Dibya Prakash Jena, Moussa Leblouba
Summary: In this research, a single-element mechanical metamaterial is designed to achieve quasi-zero-stiffness (QZS) property, which eliminates the need for a combination of positive and negative stiffness elements, simplifies the model, and improves load-bearing capacity. The QZS mechanism is solely based on the geometrical configuration of the flexible beam, making it material independent. Mathematical modeling, Harmonic-Balance method, and experimental validation confirm the vibration isolation capability of the proposed model in low-frequency ranges. Stability analysis is also performed.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Physics, Fluids & Plasmas
Geun Ju Jeon, Joo Hwan Oh
Summary: In this study, a chevron-beam-based nonlinear-tunable elastic metamaterial is proposed, which can tune the nonlinear parameters. Instead of enhancing or suppressing nonlinear phenomena or slightly tuning nonlinearities, the proposed metamaterial directly tunes its nonlinear parameters, allowing for broader manipulation of nonlinear phenomena.
Article
Engineering, Mechanical
Xian Cheng, Yi Zhang, Xin Ren, Dong Han, Wei Jiang, Xue Gang Zhang, Hui Chen Luo, Yi Min Xie
Summary: Auxetic materials are mechanical metamaterials that exhibit lateral expansion under tension and contraction under compression. Enhancing the stiffness of these materials is a focus of research to expand their potential applications. This study designs re-entrant unit cells with variable stiffness factors and verifies their accuracy through experimental and numerical analyses. The findings demonstrate that the compression points of the proposed structures can be quantitatively tuned, providing a new method for optimizing the design of unit cells with negative Poisson's ratio.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Mechanical
Yilin Zhu, Songhui Jiang, Qi Zhang, Jian Li, Chao Yu, Chuanzeng Zhang
Summary: Missing rib auxetics with a reinforced central core may have tunable negative Poisson's ratios and other mechanical parameters. In this work, a novel enhanced tetra-missing rib honeycomb metamaterial is proposed. The proposed metamaterial exhibits tailorable Poisson's ratios and elastic and shear moduli in wide ranges. The stiffness of the present design is improved remarkably compared to the previously developed enhanced anti-tetra-missing rib honeycomb.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Civil
Xiang Yu Zhang, Xin Ren, Yi Zhang, Yi Min Xie
Summary: An auxetic metamaterial composed of novel re-entrant unit cells was proposed and achieved more stable and significant auxetic behavior by adding wedge-shaped parts to the conventional re-entrant structure. The mechanical and deformation characteristics of this new material were investigated experimentally and numerically, and the influence of the wedge-shaped part was analyzed through a parametric study.
THIN-WALLED STRUCTURES
(2022)
Article
Nanoscience & Nanotechnology
N. S. Saravana Jothi, A. Hunt
Summary: Metamaterials are artificially structured materials with unique properties that do not exist in nature. Mechanical metamaterials aim to overcome limitations by embedding actuation into the unit elements, enabling control of material properties and mechanical states. This study proposes and investigates an active mechanical metamaterial concept that can actively control force and deformation distribution within its lattice.
Article
Mechanics
Yutong Fu, Wei Liu
Summary: This paper proposes a novel mechanical metamaterial with controllable stiffness based on curved beam unit cells, which are mechanically analyzed, optimized, and fabricated using 3D printing techniques. The multi-layered mechanical metamaterials exhibit advantages of improved specific stiffness and reduced spatial volume, providing a new design principle for the development of mechanical metamaterials.
COMPOSITE STRUCTURES
(2021)
Article
Mechanics
Xi Hai Ni, Wei Jiang, Xue Gang Zhang, Dong Han, Xing Chi Teng, Jian Hao, Hang Hang Xu, Xin Ren
Summary: The novel auxetic honeycomb (NAH) combines an original re-entrant hexagonal honeycomb (RH) with cross-chiral honeycomb (CH) to overcome the limitations of unstable deformation and low stiffness. The static mechanical properties and deformation behavior of NAH are investigated experimentally and numerically, and the energy absorption and deformation behavior under different impact loadings are also studied. The results demonstrate that NAH has superior energy absorption and impact resistance compared to RH and CH.
COMPOSITE STRUCTURES
(2023)
Article
Physics, Multidisciplinary
Zheng Wu, Jianlin Yi, Rongyu Xia, Jianlin Chen, Zheng Li
Summary: A novel non-Hermitian piezoelectric metamaterial beam is proposed to achieve tunable zero reflection and perfect absorption of flexural waves. The influence of electrical boundary conditions on the zero reflection and the relationship between zero reflection and exceptional point are analyzed. The desired frequency zero reflection is realized using a genetic algorithm and experimentally validated. The non-Hermitian metamaterial beam can also achieve unidirectional absorption of flexural waves.
FRONTIERS IN PHYSICS
(2022)
Article
Engineering, Civil
Songliang Zhang, Jia Lou, Hui Fan, Jianke Du
Summary: A new nonlinear acoustic metamaterial beam is designed and analyzed in this paper. The system consists of a homogeneous beam with periodic resonant units attached on the top surface. An analytical model is developed to evaluate the amplitude-frequency response, dispersion, and band gaps of the flexural wave. The effects of linear and nonlinear stiffness and resonator arrangement on the frequency band structure are discussed. The numerical results validate the developed analytical model and demonstrate the enhanced tunability of the band gap due to system nonlinearity.
ENGINEERING STRUCTURES
(2023)
Article
Engineering, Civil
Shaoyu Zhao, Yingyan Zhang, Yihe Zhang, Jie Yang, Sritawat Kitipornchai
Summary: This paper proposes a novel functionally graded beam made of graphene origami-enabled auxetic metamaterials and investigates its nonlinear free vibration characteristics. The parameters such as graphene origami content and distribution pattern can effectively tune the nonlinear frequencies of the beam.
THIN-WALLED STRUCTURES
(2022)
Article
Engineering, Civil
Shaoyu Zhao, Yingyan Zhang, Helong Wu, Yihe Zhang, Jie Yang
Summary: This paper examines the buckling and postbuckling properties of functionally graded graphene origami-enabled auxetic metallic metamaterial beams. It shows that graphene origami contributes to the formation of the auxetic metal metamaterial and its tunable buckling and postbuckling properties. This provides significant insights into the design of high-performance structures.
ENGINEERING STRUCTURES
(2022)
Article
Chemistry, Multidisciplinary
Jing Li, Hongjie Fan, Han Ye, Tiesheng Wu, Yuhang Sun, Xueyu Wang, Yumin Liu
Summary: This paper proposes a stretchable metasurface with both multifunctionality and tunability, which has great potential for applications in optical devices. By changing the period Px of the metasurface, the functions can be switched and the splitting angle can be adjusted.
Article
Engineering, Mechanical
Yi Zhang, Xin Ren, Dong Han, Xian Cheng, Wei Jiang, Xue Gang Zhang, Xiang Yu Zhang, Yi Min Xie
Summary: This study examines the static performance and energy absorption of 2D metallic auxetic metamaterials designed by tuning densification strain. The concept of variable stiffness factor (VSF) is extended to variable energy factor (VEF) for tunable energy absorption. Results show that the designed structure has the desired mechanical properties and effective energy absorption under different crushing velocities.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Engineering, Civil
Lei Xiao, Oreste S. Bursi, Meng Wang, Satish Nagarajaiah, Feifei Sun, Xiu-Li Du
Summary: This paper proposes two novel configurations of metamaterial beams, namely monatomic and diatomic, by combining negative stiffness absorbers (NSAs) and rotation of flexural beams. The advantage of using rotation instead of transversal deformation for achieving low-frequency band gap is acknowledged. The behavior of the rotational unit cell with NSAs is systematically investigated, considering parameters such as negative stiffness ratio, outrigger length, and damping ratio. Moreover, the damping magnification effect of NSAs provides substantial damping ratios for the passband. In this way, a wider band gap can be achieved through the band-gap merging effect in the proposed diatomic configuration, mitigating waves due to NSAs' damping magnification effect.
ENGINEERING STRUCTURES
(2023)
Article
Physics, Applied
Yue Bai, Limin Gu, Xiaole Wang, Zhenyu Huang
Summary: A passive, non-closed and remote scheme is proposed for omnidirectional reduction of sound power radiated from vibrating sources by designing acoustic superscatterer based on transformation media. Theoretical analysis and numerical simulations confirm the effectiveness of using acoustic superscatterer to suppress sound radiation power generated by dipolar sources. The study shows that arranging no more than two acoustic superscatterers can suppress 90% of sound radiation power in all directions of the dipole axis.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Physics, Applied
Jin Chen, Hongchen Chu, Yixing Huang, Yun Lai, Mingji Chen
Summary: This paper proposes a novel design of an ultra-wideband planar Luneburg lens (PLL) that utilizes all dielectric lightweight radially symmetric periodic gradient metamaterial. The presented lens achieves highly directional emission and achromatic sub-diffraction focusing. Experimental results confirm the effectiveness and superiority of the proposed design methodology, demonstrating the great potential of the PLL for practical deployment.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Physics, Multidisciplinary
Tongtong Song, Jie Luo, Yun Lai
Summary: This study demonstrates a potential approach to achieve zero-spacing photonic waveguides by designing pure-dielectric photonic crystal waveguides with shifted spatial dispersion and arranging them with normal dielectric waveguides alternately. This finding opens up a new avenue for ultra-compact photonic waveguides and circuits with 100% space utilization efficiency.
Article
Acoustics
Qi Wang, Jun Lan, Zhaoyu Deng, Yun Lai, Xiaozhou Liu
Summary: In this study, a heterogeneous structure acoustic leaky-wave antenna (LWA) is proposed to achieve spatial directional radiation and acoustic source localization. The designed antenna has unique frequency-scanning characteristics for directional radiation of sound waves with diverse incident frequencies. Additionally, it exhibits explicit directional frequency characteristics for spatial acoustic source localization, showing potential applications in high-precision acoustic source localization.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2023)
Article
Multidisciplinary Sciences
Bo Xiong, Yu Liu, Yihao Xu, Lin Deng, Chao-Wei Chen, Jia-Nan Wang, Ruwen Peng, Yun Lai, Yongmin Liu, Mu Wang
Summary: By introducing engineered noise to the precise solution of Jones matrix elements, we have surpassed the fundamental limit of polarization multiplexing capacity of metasurfaces. Through experiments, we have achieved up to 11 independent holographic images using a single metasurface illuminated by visible light with different polarizations, which is the highest reported capacity for polarization multiplexing. With the combination of position multiplexing, the metasurface is capable of generating 36 distinct images, forming a holographic keyboard pattern. This discovery opens up new possibilities for high-capacity optical display, information encryption, and data storage.
Article
Crystallography
Qinglei Zeng, Shenlian Gao, Yun Lai, Xiaozhou Liu
Summary: In this paper, we demonstrate the remarkable improvement in the directionality of acoustic radiation at low frequencies by using acoustic metamaterials arranged as an array of quadrupoles, compared with previous metamaterials arranged as monopole and dipole structures. The directivity can be adjusted by changing the characteristic parameter and symmetry of the structure, providing a flexible method of adjusting radiation directions. Furthermore, the directionality can be further improved by constructing a linear array. This work establishes the control of acoustic radiation via quadrupolar metamaterials.
Article
Optics
Shuai Lin, Hao Luo, Hainan He, Hongchen Chu, Yun Lai
Summary: In this work, broadband binary-reflection-phase metasurfaces with undistorted transmission wavefront are realized by leveraging mirror symmetry in the metasurface design. The cross-polarized reflection can be flexibly manipulated without distorting the wavefront in transmission by designing the binary-phase pattern induced in the cross-polarized reflection. The experimental validation of reflected-beam splitting and undistorted transmission wavefront in a broad bandwidth from 8 GHz to 13 GHz is presented.
Article
Nanoscience & Nanotechnology
Wenjie Ji, Jie Luo, Hongchen Chu, Xiaoxi Zhou, Xiangdong Meng, Ruwen Peng, Mu Wang, Yun Lai
Summary: By using epsilon-near-zero materials as claddings, the crosstalk between adjacent waveguides in photonic integrated circuits can be effectively prevented, leading to ultra-compact waveguide systems with extremely thin thickness.
Article
Nanoscience & Nanotechnology
Yongxin Jing, Hongchen Chu, Bo Huang, Jie Luo, Wei Wang, Yun Lai
Summary: The scattering matrix is a mathematical representation of scattering characteristics, but it lacks analytical forms for scatterers without high symmetry. We developed a deep neural network (DNN) that can calculate the scattering matrix of asymmetric scatterers thousands of times faster than finite element solvers. The DNN satisfies fundamental physical principles and enables inverse design using the gradient descent algorithm.
Article
Physics, Applied
Yi-jun Guan, Cheng-hao Wu, Qiao-rui Si, Yong Ge, Hong-xiang Sun, Yun Lai, Shou-qi Yuan
Summary: A low-frequency acoustic absorber has been experimentally demonstrated by using double split-ring resonators backed with a rigid wall. This absorber achieves near-perfect sound absorption at a subwavelength thickness and can increase the bandwidth by assembling supercells with distinct structure parameters.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Optics
Tianyu Hou, Xiangteng Li, Hao Luo, Yufeng Hao, Hongchen Chu, Yun Lai
Summary: This study proposes a wireless communication scheme using an optically-transparent metasurface to construct a functionalized metal window, which can significantly enhance the intensity of microwave signals and improve network and data transfer speeds.
Article
Optics
Jin Qin, Hainan He, Changqing Xu, Jie Luo, Yun Lai
Summary: Zero-index materials, specifically epsilon-near-zero (ENZ) gratings, have attracted significant scientific interest due to their unique polarization selectivity and blocking capability. Hybrid gratings combining perfect conductors and ENZ materials can effectively block omnidirectional electromagnetic waves of any polarization. Our research presents a promising approach for flexible polarization manipulation using ENZ gratings.
Article
Physics, Multidisciplinary
Rui Zhang, Kaiqi Wang, Xiaole Wang, Xudong Luo, Chunyu Zhao
Summary: This study presents a reconfigurable electromagnetic metamaterial (REMM) composed of spiral copper-clad unit cells with micro-tunable capacitors for precise control of electromagnetic properties. Experimental results demonstrate its wide frequency adjustment range and desirable magnetic field manipulation in wireless power transfer systems.
Article
Chemistry, Physical
Tianyu Hou, Di Li, Yan Qu, Yufeng Hao, Yun Lai
Summary: This study reports the large-scale synthesis of molybdenum disulfide (MoS2) thin films, accompanied by the formation of amorphous carbon layers. It confirms the combination of polycrystalline MoS2 with extraneous amorphous carbon layers and demonstrates the transformation of traditional n-type MoS2 into p-type semiconductors due to carbon incorporation. This unexpected behavior expands our understanding of TMDC properties and opens up new avenues for exploring novel device applications.
Article
Nanoscience & Nanotechnology
Zhonghan Fei, Jun Lan, Menyang Gong, Yun Lai, Xiaozhou Liu
Summary: In this paper, an unbalanced gain-loss acoustic metasurface is designed as an energy amplifier and can be used in acoustic signal detection. By combining two of these metasurfaces, an acoustic negative refraction system is established, allowing for negative refraction, focusing, and imaging. This work provides a new approach to using gain/loss materials and achieving multifunctionality without complex design.
