Multi-bionic mechanical metamaterials: a composite of FCC lattice and bone structures

2021 ◽  
pp. 106857
Author(s):  
Yu-Ling Wei ◽  
Qing-Sheng Yang ◽  
Xia Liu ◽  
Ran Tao
Keyword(s):  
Mechanical Metamaterials ◽  
Fcc Lattice ◽  
Bone Structures

Morphology of Σ3{/70.53°} grain boundaries in a C15 intermetallic compound

1994 ◽  
Vol 52 ◽  
pp. 684-685
Author(s):  
Fuming Chu ◽  
D. P. Pope ◽  
D. S. Zhou ◽  
T. E. Mitchell
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Crystallographic Analysis ◽  
Laves Phase ◽  
Second Phase ◽  
Bright Field Image ◽  
Boundary Edge ◽  
Arc Melting ◽  
Fcc Lattice ◽  
Diffraction Patterns

A C15 Laves phase, HfV2+Nb, shows promising mechanical properties and here we describe the structure of its grain boundaries. The C15 Laves phase has a fcc lattice with a=7.4Å. An alloy of composition Hf14V64Nb22 (including a C15 matrix and a second phase of V-rich bcc solution) was made by arc-melting. The alloy was homogenized at 1200°C for 120h. Preliminary study concentrated on Σ3{<110>/70.53°} grain boundaries in the C15 phase using Philips 400T and CM 30 microscopes.The most-commonly observed morphology of Σ3{<110>/70.53°} grain boundaries in the C15 phase is a faceted boundary. A bright field image (BFI) of the faceted boundary and the corresponding diffraction patterns with the grain boundary edge-on are shown in Fig. 1(a). From the diffraction patterns using a <110> zone axis for both grains, it is obvious that this is a Σ3{<110>/70.53°} grain boundary. Crystallographic analysis shows that the Σ3{<110>/70.53°} grain boundaries selectively facet with the following relationships between the two grains: {111}1//{111}2, {112}1//{112}2, {111}1//{115}2, and {001}1//{221}2.

Interpretation of the Contrast of High-Resolution Electron Microscopy Images of Ni4Mo by Means of Simulated Image Maps

1990 ◽  
Vol 48 (1) ◽  
pp. 28-29
Author(s):  
A. Thust ◽  
K. Urban
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Antiphase Boundary ◽  
High Resolution Electron Microscopy ◽  
Foil Thickness ◽  
Order Structure ◽  
Simulated Image ◽  
Resolution Electron ◽  
Fcc Lattice ◽  
Direct Interpretation

The alloy of composition Ni4Mo develops, at temperatures below 860 °C, an ordered Dla-structure which is based on the fcc-lattice. This alloy has been widely investigated with respect to its physical properties and its ordering behaviour. High resolution studies are rare and concentrated mainly on its short-range order structure. The aim of the present work was to develop a detailed understanding of image contrast and to apply the results to antiphase-boundary studies in ordered Ni4Mo by means of a JEOL 4000 EX electron microscope.In high-resolution electron microscopy, depending on defocus and foil thickness, a large variety of different images is obtained. Only a few of these allow a direct interpretation concerning the location and the type of the atoms. By computing a through-focus/through-thickness map (TFTT map) before starting experimental work it is possible to determine the proper conditions at which images can be obtained which are closely related to the projected potential.

Multi-Scale Aeroelastic Analysis of Wings with Lattice-Based Mechanical Metamaterials

2021 ◽  
Author(s):  
Natsuki Tsushima ◽  
Ryo Higuchi ◽  
Hitoshi Arizono ◽  
Masato Tamayama
Keyword(s):  
Multi Scale ◽  
Mechanical Metamaterials ◽  
Aeroelastic Analysis

Correlation analysis of the x-ray and functional parameters from the results of chevron (Austin) osteotomy for hallux valgus

2020 ◽  
pp. 54-63
Author(s):  
Ruslan Khairutdinov ◽  
Timur Minasov ◽  
Ekaterina Yakupova ◽  
Elvina Mukhametzyanova
Keyword(s):  
Hallux Valgus ◽  
Rating Scale ◽  
Metatarsophalangeal Joint ◽  
Valgus Deformity ◽  
First Metatarsophalangeal Joint ◽  
Chevron Osteotomy ◽  
Hallux Valgus Deformity ◽  
Valgus Angle ◽  
The Right ◽  
Bone Structures

Hallux valgus is characterized by the appearance and growth of a painful “lump” in the region of the first metatarsophalangeal joint, the development of forefoot corns, and inability to choose the right shoes, which leads to a significant decrease in the quality of life of these patients. Corrective osteotomies that preserve the metatarsophalangeal joint, for example Austin (Chevron) osteotomy, are usually used for hallux valgus deformity of the I, II degrees. Radiography with the study of the hallux valgus angle (HVA), the intermetatarsal angle (IMA), the distal metatarsal articular angle (DMAA) is a research method that shows the true correlation between bone structures. The correlation between the radiological and functional indicators of osteotomy allows us to determine possible recommendations for indications for surgical treatment of Hallux valgus. Correlation shows that the largest correction of hallux valgus in older patients occurs due to a small adjustment of the angle of DMMA and HVA. IMA had the best correction after Austin osteotomy among patients of a younger age, then the HVA, and the DMMA had minimum correction according to the AOFAS rating scale (Kitaoka). The revealed correlations allow us to determine the correct tactics for the treatment of hallux valgus by identifying the benefits of Austin osteotomy.

SPECIFIC CHARACTERISTICS OF BONE STRUCTURES ON CT-SCANS OF PATIENTS WITH SINONASAL INVERTED PAPILLOMAS

2019 ◽  
Vol 65 (4) ◽  
pp. 590-595
Author(s):  
Arkadiy Naumenko ◽  
Kseniya Sapova ◽  
Oleg Konoplev ◽  
Svetlana Astashchenko ◽  
Igor Chernushevich
Keyword(s):  
Computed Tomography ◽  
Tumor Recurrence ◽  
Inverted Papilloma ◽  
Ct Scans ◽  
Precise Localization ◽  
Sinonasal Inverted Papilloma ◽  
Bone Structures ◽  
Inverted Papillomas

Precise localization and excision of the originating site of a sinonasal inverted papilloma is essential for decreasing tumor recurrence. In this study we evaluated the use of preoperative computed tomography (CT) to pinpoint the attachment/origi-nating sites of the tumor.

scholarly journals Hierarchical mechanical metamaterials built with scalable tristable elements for ternary logic operation and amplitude modulation

2021 ◽  
Vol 7 (9) ◽  
pp. eabf1966
Author(s):  
Hang Zhang ◽  
Jun Wu ◽  
Daining Fang ◽  
Yihui Zhang
Keyword(s):  
Structural Diversity ◽  
Cell Number ◽  
Structural Elements ◽  
Ternary Logic ◽  
Stable States ◽  
One Dimensional ◽  
Logic Operation ◽  
Artificial Materials ◽  
Mechanical Metamaterials ◽  
Unit Cells

Multistable mechanical metamaterials are artificial materials whose microarchitectures offer more than two different stable configurations. Existing multistable mechanical metamaterials mainly rely on origami/kirigami-inspired designs, snap-through instability, and microstructured soft mechanisms, with mostly bistable fundamental unit cells. Scalable, tristable structural elements that can be built up to form mechanical metamaterials with an extremely large number of programmable stable configurations remains illusive. Here, we harness the elastic tensile/compressive asymmetry of kirigami microstructures to design a class of scalable X-shaped tristable structures. Using these structure as building block elements, hierarchical mechanical metamaterials with one-dimensional (1D) cylindrical geometries, 2D square lattices, and 3D cubic/octahedral lattices are designed and demonstrated, with capabilities of torsional multistability or independent controlled multidirectional multistability. The number of stable states increases exponentially with the cell number of mechanical metamaterials. The versatile multistability and structural diversity allow demonstrative applications in mechanical ternary logic operators and amplitude modulators with unusual functionalities.

scholarly journals Digital logic gates in soft, conductive mechanical metamaterials

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Charles El Helou ◽  
Philip R. Buskohl ◽  
Christopher E. Tabor ◽  
Ryan L. Harne
Keyword(s):  
Integrated Circuits ◽  
Electronic Materials ◽  
Polymer Networks ◽  
Conductive Polymer ◽  
Network Connectivity ◽  
Logic Gates ◽  
Boolean Logic ◽  
Digital Logic ◽  
Mechanical Metamaterials ◽  
Logic Operations

AbstractIntegrated circuits utilize networked logic gates to compute Boolean logic operations that are the foundation of modern computation and electronics. With the emergence of flexible electronic materials and devices, an opportunity exists to formulate digital logic from compliant, conductive materials. Here, we introduce a general method of leveraging cellular, mechanical metamaterials composed of conductive polymers to realize all digital logic gates and gate assemblies. We establish a method for applying conductive polymer networks to metamaterial constituents and correlate mechanical buckling modes with network connectivity. With this foundation, each of the conventional logic gates is realized in an equivalent mechanical metamaterial, leading to soft, conductive matter that thinks about applied mechanical stress. These findings may advance the growing fields of soft robotics and smart mechanical matter, and may be leveraged across length scales and physics.

Programmable mechanical metamaterials based on hierarchical rotating structures

2021 ◽  
Vol 216 ◽  
pp. 145-155
Author(s):  
Xiang Li ◽  
Rong Fan ◽  
Zhengjie Fan ◽  
Yang Lu
Keyword(s):  
Mechanical Metamaterials
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