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
Acoustics
Nikos Aravantinos-Zafiris, Frieder Lucklum, Mihail M. Sigalas
Summary: This work presents the theoretical and experimental verification of complete phononic band gaps in the Yablonovite structure with additional spheres in a face-centered cubic arrangement. Different spatial directions and polarizations were numerically and experimentally investigated to calculate the phononic band gaps in the acoustic band structure and transmission spectrum. The theoretical findings were confirmed by experimental measurements of 3D-printed prototype samples, showing good agreement and validation of complete phononic band gaps in these structures.
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
Engineering, Electrical & Electronic
Sabiju Valiya Valappil, Johannes F. L. Goosen, Alejandro M. Aragon
Summary: Ultrasonic flowmeters using transit-time ultrasonic transducers suffer from measurement errors caused by crosstalk. We propose a mounting mechanism based on a 3-D phononic crystal waveguide to mitigate crosstalk at high frequencies, improving measurement accuracy. By engineering the bandgap frequency range of the phononic crystal waveguide to match the working signal of the flowmeter, we fabricate the waveguide using additive manufacturing and achieve a 40 dB reduction in crosstalk compared to standard transducer configurations.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(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)
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, Fluids & Plasmas
B. L. Kim, C. Chong, S. Hajarolasvadi, Y. Wang, C. Daraio
Summary: In this study, the response of a one-dimensional phononic lattice with time-periodic elastic properties is investigated in both linear and nonlinear regimes using experimental, numerical and theoretical approaches. It is found that wave-number band gaps emerge under small-amplitude excitation, while large-amplitude responses are stabilized via the nonlinear nature of the magnetic interactions, resulting in a family of nonlinear time-periodic states. Controlling acoustic and elastic wave propagation by balancing nonlinearity and external modulation offers potential applications in signal processing and telecommunication devices.
Article
Physics, Applied
Sihao Han, Qiang Han, Chunlei Li
Summary: In this study, a data-driven deep learning framework is used to predict the band structure of phononic crystals and to design topological structures using a generative adversarial network. The spatial decay of evanescent waves is computed by a periodic spectral finite element method. The design process selects topologies with greater spatial attenuation. The result is an optimized topological phononic crystal with an anticipated bandgap.
JOURNAL OF APPLIED PHYSICS
(2022)
Article
Physics, Applied
Etienne Coffy, Sebastien Euphrasie, Pascal Vairac, Abdelkrim Khelif
Summary: The experimental high spatial confinement of elastic energy in a silicon phononic cantilever is achieved by using a three-row phononic crystal (PnC) strip, increasing the quality factor of a higher-order flexural resonance by a factor of 27; Numerical simulations show that the PnC reduces anchor loss and confines elastic energy inside the cantilever; Both the PnC and the cantilever are fabricated using standard clean room techniques on a silicon on insulator substrate. Optical measurements of the out-of-plane displacements are performed with a laser scanning interferometer in a frequency range around 2 MHz.
APPLIED PHYSICS LETTERS
(2021)
Review
Nanoscience & Nanotechnology
Yabin Jin, Liangshu He, Zhihui Wen, Bohayra Mortazavi, Hongwei Guo, Daniel Torrent, Bahram Djafari-Rouhani, Timon Rabczuk, Xiaoying Zhuang, Yan Li
Summary: With the growing interest in artificial materials, the demand for advanced functionalities in phononic crystals and acoustic metamaterials is increasing. Machine learning, as an important branch of artificial intelligence, provides a powerful means of achieving efficient and accurate design processes. This review summarizes recent works on the combination of phononic metamaterials and machine learning and provides an outlook on future development directions.
Article
Materials Science, Multidisciplinary
Kenny L. S. Yip, Sajeev John
Summary: Locally resonant acoustic materials are proposed for sound control by using resonant oscillators consisting of heavy mass within a light shell embedded in foam. The effective, frequency-dependent mass densities of these oscillators are derived and used to evaluate the acoustic band structure in two dimensions. The accuracy of the results is validated by comparing with exact solutions obtained through numerical simulations.
Article
Computer Science, Interdisciplinary Applications
Eric B. Chin, Amir Ashkan Mokhtari, Ankit Srivastava, N. Sukumar
Summary: This paper computes the band structure of one- and two-dimensional phononic composites using X-FEM on structured higher-order finite element meshes. By using partition-of-unity enrichment, structured finite element meshes can be used without conforming to the geometry of holes and inclusions, eliminating the need for remeshing. The method demonstrates high accuracy and optimal convergence on structured, higher-order spectral finite element meshes.
JOURNAL OF COMPUTATIONAL PHYSICS
(2021)
Article
Engineering, Multidisciplinary
Liqun Wang, Zhijie Wang, Xin Lu, Liwei Shi
Summary: In this paper, a finite element method based on the Floquet transform and local optimization semi-Cartesian grid is proposed to compute the complex band structure of phononic crystals. The method is able to calculate the complex band structures of phononic crystals with complicated scatterer shapes and has been demonstrated to be effective in the computation of anisotropic inhomogeneous medium.
APPLIED MATHEMATICAL MODELLING
(2023)
Article
Acoustics
Jianjun Wang, Yunlei Zhou, Shan Jiang
Summary: This study proposes an effective strategy to enlarge the band gaps of holey phononic crystal strips by implementing targeted synthetic adjustments and achieving larger band gaps through the synergistic action of different methods.
JOURNAL OF VIBRATION AND CONTROL
(2023)
Article
Engineering, Mechanical
Wei Guo, Shu-Yan Zhang, Yan-Feng Wang, Vincent Laude, Yue-Sheng Wang
Summary: The propagation of evanescent Lamb waves in the one-dimensional viscoelastic phononic metastrip is studied in this paper. The effect of viscosity, different cutting forms, and material properties on the complex band structure and wave distribution is investigated. The results provide a numerical and experimental foundation for practical applications of phononic metastrips.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Materials Science, Multidisciplinary
Hanlyun Cho, Jae Man Park, Junsuk Rho, Seong Jin Park
Summary: The study focused on investigating warpage defects in PIM manufacturing, revealing that the debinding heating rate has a dominant effect on structure warping and should be optimized accordingly.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Nanoscience & Nanotechnology
Niloufar Raeis-Hosseini, Junsuk Rho
Summary: The study introduces a flexible, transparent, and biocompatible resistive switching random access memory (ReRAM) based on gold-decorated chitosan. The device exhibits reliable bipolar memory performance and mechanical flexibility, making it suitable for flexible and wearable electronic devices.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Chemistry, Multidisciplinary
Gwanho Yoon, Kwan Kim, Se-Um Kim, Seunghoon Han, Heon Lee, Junsuk Rho
Summary: Printable metalenses made of a silicon nanocomposite offer high refractive index and thermal stability, suitable for intricate nanofabrication and rapid large-scale manufacturing. By optimizing the composition of the nanocomposite, the focusing efficiency of the metalenses can be further increased.
Article
Optics
Minkyung Kim, Dasol Lee, Hyukjoon Cho, Bumki Min, Junsuk Rho
Summary: This study proposes a method to achieve a large SHEL and near-unity efficiency in the microwave spectrum using anisotropic impedance mismatching, and experimentally confirms spin-dependent splitting by measuring transmission coefficients and the spatial profile of Stokes parameters.
LASER & PHOTONICS REVIEWS
(2021)
Article
Nanoscience & Nanotechnology
Dongwoo Chae, Hangyu Lim, Sunae So, Soomin Son, Sucheol Ju, Wonjoong Kim, Junsuk Rho, Heon Lee
Summary: The radiative cooler based on a nanoparticle mixture exhibits highly selective infrared emission and low solar absorption, providing a more powerful cooling effect compared to broadband emitters. The simple fabrication process generates subambient surface cooling of 2.8 degrees C and space cooling of 1.0 degrees C, outperforming broadband emitters.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Multidisciplinary Sciences
Wooik Jung, Yoon-Ho Jung, Peter V. Pikhitsa, Jicheng Feng, Younghwan Yang, Minkyung Kim, Hao-Yuan Tsai, Takuo Tanaka, Jooyeon Shin, Kwang-Yeong Kim, Hoseop Choi, Junsuk Rho, Mansoo Choi
Summary: Three-dimensional (3D) printing has revolutionized manufacturing processes in various fields. A new technique allows direct printing of metal nanostructures with flexible geometries and feature sizes down to hundreds of nanometres, using various materials.
Review
Nanoscience & Nanotechnology
Inki Kim, Renato Juliano Martins, Jaehyuck Jang, Trevon Badloe, Samira Khadir, Ho-Youl Jung, Hyeongdo Kim, Jongun Kim, Patrice Genevet, Junsuk Rho
Summary: This review discusses the technological challenges of applying nanophotonics in LiDAR, the basic principles of LiDAR and overcoming hardware limitations, the characteristics of nanophotonic platforms, and the future trends in integrating nanophotonic technologies into commercially viable, fast, ultrathin, and lightweight LiDAR systems.
NATURE NANOTECHNOLOGY
(2021)
Article
Optics
Dasol Lee, Minkyung Kim, Jongmin Lee, Byoungsu Ko, Hui Joon Park, Junsuk Rho
Summary: Dielectric grating-coupled hyperbolic metamaterials show angular selection of transmitted light and enhanced radiative emission rate, providing multifunctionalities in sensing and imaging systems.
Review
Chemistry, Analytical
Joohoon Kim, Ahsan Sarwar Rana, Yeseul Kim, Inki Kim, Trevon Badloe, Muhammad Zubair, Muhammad Qasim Mehmood, Junsuk Rho
Summary: Chiral materials have greatly impacted optical sensing by showing different optical behaviors under left or right circularly polarized light. Metasurfaces, as two-dimensional metamaterials, can enhance chiroptical response by manipulating electromagnetic fields. Applications of chiral metasurfaces include multiplexing metaholograms, metalenses, and sensors.
Article
Chemistry, Multidisciplinary
Hanlyun Cho, Heonyeong Jeong, Younghwan Yang, Trevon Badloe, Junsuk Rho
Summary: This work presents metalenses designed to enhance the luminous intensity of incoherent LEDs. By designing different phase profiles, the luminous intensity at the center and within the target detection angle region is successfully enhanced.
Article
Nanoscience & Nanotechnology
Wonseok Lee, Hyoungseok Chae, Dong Kyo Oh, Minyoung Lee, Hyunsoo Chun, Gyubeom Yeon, Jaewon Park, Joohoon Kim, Hongseok Youn, Junsuk Rho, Jong G. Ok
Summary: SPEEDIN is a facile and scalable fabrication technique for producing highly durable electronics, utilizing dynamic nanoinscribing and metal nanoparticle solution coating to embed metal structures with high reliability and durability.
MICROSYSTEMS & NANOENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Jeonghoon Park, Geon Lee, Dongwoo Lee, Miso Kim, Junsuk Rho
Summary: In this study, a double-focusing flexural energy harvesting platform is proposed, which utilizes periodic structures to control elastic waves and enhance harvesting performance. By using a gradient-index lens and an elastic Bragg mirror, the output voltage and power of the harvesting platform are significantly increased compared to a bare plate.
Article
Chemistry, Physical
Minkyung Kim, Dasol Lee
Summary: In this study, the interface-independent and strengthened spin Hall effect of light was achieved by using a single-layered dielectric metasurface. Numerical simulation results confirmed that the anisotropic geometry of the metasurface induced phase-reversed reflection for one linear polarization and phase-preserved reflection for the other, thereby strongly strengthening the reflection of the spin-Hall-shifted beam. Our work will pave a route toward the precise displacement of the beam at the nanoscale without perturbing its polarization state.
Review
Materials Science, Multidisciplinary
Joohoon Kim, Younghwan Yang, Trevon Badloe, Inki Kim, Gwanho Yoon, Junsuk Rho
Summary: Metasurfaces made of subwavelength structures, known as meta-atoms, have been attracting attention for their advantages in high-resolution holographic images, large field of view, and compact device volume. In this review, metasurface holography is classified based on meta-atom design methodologies, which can expand hologram functionalities. The interaction of light and matter in metasurface systems is described using the Jones matrix to explain modulations of light amplitude, phase, and polarization.
Article
Nanoscience & Nanotechnology
Chunghwan Jung, Younghwan Yang, Jaehyuck Jang, Trevon Badloe, Taejun Lee, Jungho Mun, Seong-Won Moon, Junsuk Rho
Summary: Structural coloration using metasurfaces has been researched to improve the limitations of conventional color printing, achieving higher resolution, lower toxicity, and increased durability. A switchable structural coloration with polarization-sensitive metasurfaces enables full-colored images to be displayed and hidden, with near-zero scattering when colors are turned-off.
