Article
Engineering, Mechanical
Milan Cajic, Johan Christensen, Sondipon Adhikari
Summary: Topological phononic crystals in the mechanical setup have become a topic of great interest due to their applicability in various engineering systems. This study investigates band transition and topological interface modes in a beam array system, as well as the effects of introduced defect masses and inerters on interface states. The results provide insight into the influence of inerter devices on interface states in complex periodic elastic systems.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Physics, Applied
Oluwaseyi Muhammad, Oluwaseyi Ogun, John Kennedy
Summary: This study developed a deep learning based autoencoder to inversely design topological phononic beams. By studying the topologically protected interface state, the characteristics of the interface modes were determined. The network prediction was validated by finite element numerical simulations and experimental tests.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Masoud Taheri Jam, Hossein M. Shodja, Mahsa Sanati
Summary: Nanoscopic interface deformations have a significant impact on the phononic band-structure of a superlattice. This study introduces a mixed variational method based on surface/interface elastodynamics theory to consider local deformations at the interfaces of the layers in one-dimensional hypersonic phononic crystals. The phononic band-structures of HfO2-ZrO2 multilayer stack and ultrathin Pd-layer stack are calculated with consideration of interface deformations and compared with results without considering interface deformations. The effect of nanoscopic interface deformability on the band gap and negative refraction is addressed, providing a pathway for designing advanced metamaterials operating in gigahertz or terahertz frequency ranges.
MECHANICS OF MATERIALS
(2022)
Article
Physics, Multidisciplinary
Jinfeng Zhao, Chenwen Yang, Weitao Yuan, Danmei Zhang, Yang Long, Yongdong Pan, Hong Chen, Zheng Zhong, Jie Ren
Summary: This study reports the observation of local elastic valley spin and the previously overlooked hidden elastic spin-valley locking mechanism. By controlling the elastic spin, the direction of valley phonon state transmission along the interface can be reversed. This discovery offers a new tool for exploring topological metamaterials.
PHYSICAL REVIEW LETTERS
(2022)
Article
Engineering, Mechanical
Seongmin Park, Wonju Jeon
Summary: We propose deep-subwavelength phononic beams that support topological interface states (TISs) at ultra-low frequencies. The beams are designed using unit cells with acoustic black hole (ABH) configurations to obtain the first band gap at low frequencies, where the unit cell size is much smaller than the wavelength of the wave. By modifying the ABH configuration and breaking the inversion symmetry of the unit cell, we control the topological phases of the phononic beams and connect two topologically distinct beams to produce the TIS in their low band gaps.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2023)
Article
Mechanics
Zhenyu Chen, Guifeng Wang, C. W. Lim
Summary: This manuscript proposes a new approach to break the spatial symmetry in beam systems by tuning the elastic stiffnesses of periodically alternated elastic supports. The bending characteristics of a phononic crystal beam on such a support system are studied using experimental and numerical methods. The results show the appearance of a bandgap and capture mode shape inversion and Zak phase transition. Furthermore, the topologically protected interface modes in an array constructed with periodically arranged unit cells are analyzed. This general mechanism can potentially be applied to other mechanical and dynamic systems to establish topological phase transitions.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Engineering, Mechanical
Zhenyu Chen, Guifeng Wang, Fan Shi, C. W. Lim
Summary: This study proposes a new type of active sandwiched PnC beam for inducing topological geometric phase transition and topologically protected interface modes. Theoretical band structure is derived through analytical modeling and validated through numerical analysis. The study finds that the robust interface modes are immune to defects and disorders.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Engineering, Mechanical
Zhenyu Chen, Weijian Zhou
Summary: This paper investigates thermally tunable elastic wave transport with controllable topological properties in a thin plate. By using ferroelectric ceramics and temperature variation, topologically protected elastic waveguide devices can be designed to manipulate band properties and working frequencies. The results show that the topological phononic crystal plate with A-shaped prisms realizes broadband interface modes with high quality factors.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2023)
Article
Acoustics
Seongmin Park, Wonju Jeon
Summary: Researchers proposed a tapered phononic beam with a unit cell consisting of two identical uniform parts and a thickness- and width-varying part. By controlling the geometrical parameters, the phononic beam achieved an ultra-broad and ultra-low frequency band gap from 3.6 Hz to 237.9 Hz.
JOURNAL OF SOUND AND VIBRATION
(2021)
Article
Physics, Applied
Peng Zhang, Han Jia, Yuzhen Yang, Jien Wu, Jun Yang
Summary: This study proposes a one-dimensional piezoelectric topological phononic crystal (PTPC) with electrically tunable working frequency by introducing an external capacitor circuit. By appropriately tuning the capacitances to actively control the bandgap frequency, heterostructured PTPCs with high-energy-capacity ETIMs and electrically tunable working frequency range and bandwidth are constructed. This work paves the way for wide engineering applications in acoustic sensing enhancement, nondestructive testing, energy harvesting, information processing, and reconfigurable topological wave transports.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Anchen Ni, Zhifei Shi
Summary: In this work, a novel inertial amplified topological metamaterial beam is proposed to overcome the large mass limitation for low-frequency topologically protected interface modes. The dynamic characteristics of the system are investigated through detailed analytical and numerical studies. The existence of the topologically protected interface modes is verified through transmission simulation. The lower-frequency Dirac cone and wider local resonance bandgaps are obtained without sacrificing total stiffness or increasing total mass.
JOURNAL OF APPLIED PHYSICS
(2023)
Article
Physics, Applied
Shu-Yan Zhang, Yan-Feng Wang, Yue-Sheng Wang
Summary: This paper investigates evanescent surface waves propagating in a one-dimensional surface phononic crystal, revealing the transition of surface waves to bulk waves with increasing frequency and pillar height. It also discusses the variations in the generation mechanism of the first bandgap and the transmission properties when viscosity is introduced.
JOURNAL OF APPLIED PHYSICS
(2021)
Review
Nanoscience & Nanotechnology
Yafeng Chen, Zhihao Lan, Zhongqing Su, Jie Zhu
Summary: This article discusses the recent advances and achievements in the development of photonic and phononic topological insulators using inverse design methodologies. It covers one-dimensional TIs, TIs based on the quantum spin Hall effect and quantum valley Hall effect, as well as high-order TIs in lattices with diverse symmetries. Several inversely designed photonic and phononic TIs with superior performance are showcased, and the future of this emerging research field is also discussed.
Article
Nanoscience & Nanotechnology
Samuli Heiskanen, Tuomas A. Puurtinen, Ilari J. Maasilta
Summary: Controlling thermal transport at the nanoscale is crucial for various applications. This study demonstrates that thermal conductance can be controlled using three-dimensional phononic crystals, without the need for suspension. Experimental results show that at sub-Kelvin temperatures, these structures can enhance thermal conductivity.
Article
Astronomy & Astrophysics
Armand Leclerc, Guillaume Laibe, Pierre Delplace, Antoine Venaille, Nicolas Perez
Summary: Stellar oscillations can have topological properties, as revealed by establishing a novel parallel between stars and topological insulators. The changes in the acoustic-buoyant frequency are connected to the existence of topological modes within stars, which cross the frequency gap and exhibit different behaviors at low and high harmonic degree.
ASTROPHYSICAL JOURNAL
(2022)
Article
Mechanics
C. Sugino, M. Ruzzene, A. Erturk
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2020)
Article
Engineering, Mechanical
M. A. Campana, M. Ouisse, E. Sadoulet-Reboul, M. Ruzzene, S. Neild, F. Scarpa
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2020)
Article
Physics, Applied
Yiwei Xia, Alper Erturk, Massimo Ruzzene
PHYSICAL REVIEW APPLIED
(2020)
Article
Physics, Multidisciplinary
Matheus I. N. Rosa, Massimo Ruzzene
NEW JOURNAL OF PHYSICS
(2020)
Article
Materials Science, Multidisciplinary
Matheus INc Rosa, Matteo Mazzotti, Massimo Ruzzene
Summary: The study focuses on exceptional points in continuous elastic media and their potential application in detecting mass and stiffness perturbations. By introducing balanced gain and loss to induce degenerate states, the sensitivity of the system is enhanced, making it promising for applications involving sensing of disturbances such as point masses and surface cracks.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Acoustics
Matteo Mazzotti, Christopher Sugino, Eetu Kohtanen, Alper Erturk, Massimo Ruzzene
Summary: The study investigates and characterizes high order Lamb wave modes in a human skull to estimate the mechanical properties of cortical and trabecular bones, using direct contact excitation and infrared laser vibrometry. The results demonstrate the use of high order Lamb waves to understand the wave properties of a human skull and estimate the mechanical properties of bones.
Article
Crystallography
Mohit Gupta, Massimo Ruzzene
Article
Physics, Multidisciplinary
Yiwei Xia, Emanuele Riva, Matheus I. N. Rosa, Gabriele Cazzulani, Alper Erturk, Francesco Braghin, Massimo Ruzzene
Summary: The experimental demonstration shows temporal pumping of elastic waves in an electromechanical waveguide, enabling the generation and control of edge states through temporal modulation of stiffness. The framework allows for controllable transfer of edge states from one boundary to the other, opening up new avenues for information manipulation and transport through elastic waves. This study also explores higher-dimensional topological physics using virtual dimensions mapped to time in electromechanical systems.
PHYSICAL REVIEW LETTERS
(2021)
Article
Acoustics
Christopher Sugino, Massimo Ruzzene, Alper Erturk
Summary: In this study, guided waves in a human cadaver skull were investigated through experiments and computational simulations. Different wave modes and dispersion properties were characterized through analysis of experimental data. The leaky and non-leaky wave behavior of degassed skull with water loading in the cranial cavity was also explored, with successful excitation of leaky Lamb waves confirmed for higher-order wave modes with phase velocity faster than the speed of sound in water.
ULTRASOUND IN MEDICINE AND BIOLOGY
(2021)
Article
Physics, Applied
Zhoufu Zheng, Jianfei Yin, Jihong Wen, Dianlong Yu
Summary: A one-dimensional locally resonant phononic crystal with twin resonators is designed, showing the potential for multiple topological interface states under certain conditions. This work provides guidelines for the design of low-frequency elastic topological systems.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Engineering, Mechanical
Danilo Beli, Matheus Inguaggiato Nora Rosa, Carlos De Marqui Jr, Massimo Ruzzene
Summary: Periodic configurations have dominated the design of phononic and elastic-acoustic metamaterial structures. Quasicrystals lack translational symmetry but have unrestricted rotational symmetries, leading to unexplored mechanical and dynamic properties. Higher order symmetries in quasicrystals allow for high equivalent stiffness characteristics and nearly isotropic wave propagation, with potential for novel material designs.
EXTREME MECHANICS LETTERS
(2021)
Article
Acoustics
Matteo Mazzotti, Eetu Kohtanen, Alper Erturk, Massimo Ruzzene
Summary: The study investigates the dispersion properties of leaky Lamb waves in cranial bone, where energy is leaked into the brain when waves propagate faster than the speed of sound in surrounding fluids. Numerical analysis shows that leakage angles correspond to those predicted by an equivalent waveguide model, and two main leaky branches are observed in the dispersion spectrum. Experimental tests on immersed parietal bone confirm these observations.
IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL
(2021)
Article
Physics, Applied
Zhoufu Zheng, Jianfei Yin, Jihong Wen, Dianlong Yu
Summary: This study reports the theoretical modeling and experimental realization of higher-order topological insulators in elastic locally resonant metamaterials (LRMs). By exploring the interplay between local resonance couplings and nontrivial band topology, various higher-order topological corner states (TCSs) are constructed. These TCSs exhibit frequency-selective and dimension-switching abilities, providing effective routes for the design of deep sub-wavelength topological devices.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Christopher Sugino, Massimo Ruzzene, Alper Erturk
Article
Materials Science, Multidisciplinary
Emanuele Riva, Matheus I. N. Rosa, Massimo Ruzzene
