Read by QxMD icon Read


Weixuan Zhang, Kaiyang Cheng, Chao Wu, Yi Wang, Hongqiang Li, Xiangdong Zhang
Metamaterials, artificially structured electromagnetic (EM) materials, have enabled the realization of many unconventional EM properties not found in nature, such as negative refractive index, magnetic response, invisibility cloaking, and so on. Based on these man-made materials with novel EM properties, various devices are designed and realized. However, quantum analog devices based on metamaterials have not been achieved so far. Here, metamaterials are designed and printed to perform quantum search algorithm...
November 17, 2017: Advanced Materials
Alejandro Gutiérrez, Metin G Guney, Gary K Fedder, Lilian P Dávila
Diatoms are microscopic algae with intricate shell morphologies and features ranging from the nanometer to the micrometer scale, which have been proposed as templates for drug delivery carriers, optical devices, and metamaterials design. Several studies have found that diatom shells show unique mechanical properties such as high specific strength and resilience. One hypothesis is that these properties stem from the structural arrangement of the material at the nanometer and micrometer length scales, challenging the concept between what constitutes a "material" versus a "structure"...
November 17, 2017: Biomaterials Science
Maria Letizia De Marco, Sanaa Semlali, Brian A Korgel, Philippe Barois, Glenna L Drisko, Cyril Aymonier
Metamaterials have optical properties that are unprecedented in nature. They have opened new horizons in light manipulation, with the ability to bend, focus, and completely reflect, transmit or absorb an incident wave front. Optically active metamaterials in particular could be used for applications ranging from 3D information storage, more efficient photovoltaic cells, high security watermarks, and fiber optics. Silicon (Si) particles are some of the most promising building blocks for optically active metamaterials, with high scattering efficiency coupled to low light absorption for visible frequencies...
November 16, 2017: Angewandte Chemie
Qian Ma, Huan Hu, Eric Huang, Zhaowei Liu
We present a new far-field super-resolution imaging approach called compressive spatial to spectral transformation microscopy (CSSTM). The transformation encodes the high-resolution spatial information to a spectrum through illuminating sub-diffraction-limited and wavelength-dependent patterns onto an object. The object is reconstructed from scattering spectrum measurements in the far field. The resolution of the CSSTM is mainly determined by the materials used to perform the spatial to spectral transformation...
November 15, 2017: Nanoscale
Emilio Turco, Ivan Giorgio, Anil Misra, Francesco dell'Isola
One of the most interesting challenges in the modern theory of materials consists in the determination of those microstructures which produce, at the macro-level, a class of metamaterials whose elastic range is many orders of magnitude wider than the one exhibited by 'standard' materials. In dell'Isola et al. (2015 Zeitschrift für angewandte Mathematik und Physik66, 3473-3498. (doi:10.1007/s00033-015-0556-4)), it was proved that, with a pantographic microstructure constituted by 'long' micro-beams it is possible to obtain metamaterials whose elastic range spans up to an elongation exceeding 30%...
October 2017: Royal Society Open Science
Hyung Jin Lee, Je-Ryung Lee, Seung Hwan Moon, Tae-Jin Je, Eun-Chae Jeon, Kiyean Kim, Yoon Young Kim
The polarization anomaly refers to the polarization transition from longitudinal to shear modes along an equi-frequency contour of the same branch, which occurs only in some anisotropic elastic media, but the lack of natural materials exhibiting desired anisotropy makes its utilization impossible for potential novel applications. In this paper, we present a unique, non-resonant type elastic metamaterial made of off-centered, double-slit unit cells. We show that its wave polarization characteristics that determine the desired anomalous polarization for a certain application are tailorable...
November 13, 2017: Scientific Reports
Feng Wu
We present studies on an electric field focuser comprised of annular epsilon-near-zero metamaterials (ENZMs) and inner free space. According to effective medium theory, annular ENZMs can be realized via annular metal-dielectric multilayers. In practice, we choose silver and air to design the focuser. Our numerical simulations demonstrate that the electric field can be focused on a fixed point, regardless of the number and location of electromagnetic sources in annular multilayers, which might be helpful for laser ignition...
November 10, 2017: Applied Optics
Mai Desouky, Ahmed M Mahmoud, Mohamed A Swillam
Noble Metals such as Gold and Silver demonstrated for mid IR metamaterials have suffered many obstacles such as: high losses and lack of tunability. The application of doped semiconductors has allowed overcoming the tunability restriction, besides, possessing lower losses as compared to metals. In addition, doped semiconductors have small magnitude of negative real permittivity which is required to realize mid IR Hyperbolic Metamaterials (HMMs). We theoretically demonstrate super focusing based on an all Semiconductor planar HMM using InAs heterostructure...
November 10, 2017: Scientific Reports
Simon Yves, Fabrice Lemoult, Mathias Fink, Geoffroy Lerosey
Graphene, a honeycomb lattice of carbon atoms ruled by tight-binding interaction, exhibits extraordinary electronic properties due to the presence of Dirac cones within its band structure. These intriguing singularities have naturally motivated the discovery of their classical analogues. In this work, we present a general and direct procedure to reproduce the peculiar physics of graphene within a very simple acoustic metamaterial: a double lattice of soda cans resonating at two different frequencies. The first triangular sub-lattice generates a bandgap at low frequency, which induces a tight-binding coupling between the resonant defects of the second honeycomb one, hence allowing us to obtain a graphene-like band structure...
November 10, 2017: Scientific Reports
S M Ahmadi, R Hedayati, Y Li, K Lietaert, N Tümer, A Fatemi, C D Rans, B Pouran, H Weinans, A A Zadpoor
Additive manufacturing (AM) techniques enable fabrication of bone-mimicking meta-biomaterials with unprecedented combinations of topological, mechanical, and mass transport properties. The mechanical performance of AM meta-biomaterials is a direct function of their topological design. It is, however, not clear to what extent the material type is important in determining the fatigue behavior of such biomaterials. We therefore aimed to determine the isolated and modulated effects of topological design and material type on the fatigue response of metallic meta-biomaterials fabricated with selective laser melting...
November 7, 2017: Acta Biomaterialia
Bo Liu, Chaojun Tang, Jing Chen, Zhendong Yan, Mingwei Zhu, Yongxing Sui, Huang Tang
We numerically investigate the coupling effects of surface plasmon polaritons (SPPs) and magnetic dipole (MD) resonances in metamaterials, which are composed of an Ag nanodisk array and a SiO2 spacer on an Ag substrate. The periodicity of the Ag nanodisk array leads to the excitation of SPPs at the surface of the Ag substrate. The near-field plasmon interactions between individual Ag nanodisks and the Ag substrate form MD resonances. When the excitation wavelengths of SPPs are tuned to approach the position of MD resonances by changing the array period of Ag nanodisks, SPPs and MD resonances are coupled together into two hybridized modes, whose positions can be well predicted by a coupling model of two oscillators...
November 9, 2017: Nanoscale Research Letters
Nadège Kaina, Alexandre Causier, Yoan Bourlier, Mathias Fink, Thomas Berthelot, Geoffroy Lerosey
Many efforts have been devoted to wave slowing, as it is essential, for instance, in analog signal computing and is one prerequisite for increased wave/matter interactions. Despite the interest of many communities, researches have mostly been conducted in optics, where wavelength-scaled structured composite media are promising candidates for compact slow light components. Yet their structural scale prevents them from being transposed to lower frequencies. Here, we propose to overcome this limitation using the deep sub-wavelength scale of locally resonant metamaterials...
November 8, 2017: Scientific Reports
Uttam Manna, Jung-Hoon Lee, Tian-Song Deng, John Parker, Nolan C Shepherd, Yossi Weizmann, Norbert F Scherer
Extension of the Maxwell-Faraday law of electromagnetic induction to optical frequencies requires spatially appropriate materials and optical beams to create resonances and excitations with curl. Here we employ cylindrical vector beams with azimuthal polarization to create electric fields that selectively drive magnetic responses in dielectric core-metal nanoparticle "satellite" nanostructures. These optical frequency magnetic resonances are induced in materials that do not possess spin or orbital angular momentum...
November 7, 2017: Nano Letters
Xin Fang, Jihong Wen, Bernard Bonello, Jianfei Yin, Dianlong Yu
Linear acoustic metamaterials (LAMs) are widely used to manipulate sound; however, it is challenging to obtain bandgaps with a generalized width (ratio of the bandgap width to its start frequency) >1 through linear mechanisms. Here we adopt both theoretical and experimental approaches to describe the nonlinear chaotic mechanism in both one-dimensional (1D) and two-dimensional (2D) nonlinear acoustic metamaterials (NAMs). This mechanism enables NAMs to reduce wave transmissions by as much as 20-40 dB in an ultra-low and ultra-broad band that consists of bandgaps and chaotic bands...
November 3, 2017: Nature Communications
Qian Wang, Zongpeng Wang, Zhe Li, Junyan Xiao, Hangyong Shan, Zheyu Fang, Limin Qi
Self-assembly of colloidal nanocrystals into complex superstructures offers notable opportunities to create functional devices and artificial materials with unusual properties. Anisotropic nanoparticles with nonspherical shapes, such as rods, plates, polyhedra, and multipods, enable the formation of a diverse range of ordered superlattices. However, the structural complexity and tunability of nanocrystal superlattices are restricted by the limited geometries of the anisotropic nanoparticles available for supercrystal self-assembly...
October 2017: Science Advances
Zhiyuan Fan, Zhaoxin Geng, Xiaoqin Lv, Yue Su, Yuping Yang, Jian Liu, Hongda Chen
The terahertz (THz) modulator, which will be applied in next-generation wireless communication, is a key device in a THz communication system. Current THz modulators based on traditional semiconductors and metamaterials have limited modulation depth or modulation range. Therefore, a THz modulator based on annealed tungsten disulfide (WS2, p-type) and high-resistivity silicon (n-type) is demonstrated. Pumped by a laser, the modulator presents a laser power-dependent modulation effect. Ranging from 0.25 to 2 THz, the modulation depth reaches 99% when the pumping laser is 2...
November 1, 2017: Scientific Reports
Toan Trung Nguyen, Sungjoon Lim
In this paper, a bandwidth-enhanced and wide-angle-of-incidence metamaterial absorber is proposed using a hybrid unit cell. Owing to symmetric unit cells, high absorptivity is maintained for all polarization angles. A circular-sector unit cell enables high absorptivity under the oblique incidence of both transverse electric (TE) and transverse magnetic (TM) modes. To enhance the bandwidth, we introduced a hybrid unit cell comprising four circular sectors. Two sectors resonate at 10.38 GHz, and two resonate at 10...
November 1, 2017: Scientific Reports
Davood Mousanezhad, Soroush Kamrava, Ashkan Vaziri
Origami, widely known as the ancient Japanese art of paper folding, has recently inspired a new paradigm of design for mechanical metamaterials and deployable structural systems. However, lack of rationalized design guidelines and scalable manufacturing methods has hindered their applications. To address this limitation, we present analytical methods for designing origami-based closed-loop units with inherent foldability, and for predicting their folding response (e.g., folding force, bistability, and area and volume change by folding)...
November 1, 2017: Scientific Reports
Lei Xiong, Benoit Nennig, Yves Aurégan, Wenping Bi
A metamaterial composed of a set of periodic rigid resonant inclusions embedded in a porous lining is investigated to enhance the sound attenuation in an acoustic duct at low frequencies. A transmission loss peak is observed on the measurements and corresponds to the crossing of the lower two Bloch modes of an infinite periodic material. Numerical parametric studies show that the optimum modal attenuation can be achieved at the exceptional point in the parameter plane of inclusion position and frequency, where the two lower modes merge...
October 2017: Journal of the Acoustical Society of America
Polina Marinova, Stephan Lippert, Otto von Estorff
Acoustic metamaterials appear to be of great help in the design of reliable and effective noise reduction measures in the low frequency range. The current contribution is concerned with the modeling of a low-frequency noise shield, based on a double wall arrangement, which includes membrane-type acoustic metamaterials (MAMs), considered as the most promising approach when it comes especially to the tonal noise at frequencies below 300 Hz. MAMs consist of small-sized membranes loaded with a mass. Due to their robustness and relatively simple production, MAMs have been proven to decrease the sound transmission in frequency ranges, for which poro-elastic materials have a rather negligible effect...
October 2017: Journal of the Acoustical Society of America
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"