Impedance of tissue-mimicking phantom material under compression

Abstract The bioimpedance of tissues under compression is a field in need of study. While biological tissues can become compressed in a myriad of ways, very few experiments have been conducted to describe the relationship between the passive electrical properties of a material (impedance/admittance) and its underlying mechanical properties (stress and strain) during deformation. Of the investigations that have been conducted, the exodus of fluid from samples under compression has been thought to be the cause of changes in impedance, though until now was not measured directly. Using a soft tissue-mimicking phantom material (tofu) whose passive electrical properties are a function of the conducting fluid held within its porous structure, we have shown that the mechanical behavior of a sample under compression can be measured through bioimpedance techniques.

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Concomitant control of mechanical properties and degradation in resorbable elastomer-like materials using stereochemistry and stoichiometry for soft tissue engineering

Nature Communications ◽

10.1038/s41467-020-20610-5 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Mary Beth Wandel ◽

Craig A. Bell ◽

Jiayi Yu ◽

Maria C. Arno ◽

Nathan Z. Dreger ◽

...

Keyword(s):

Mechanical Properties ◽

Drug Delivery ◽

Soft Tissue ◽

Tissue Regeneration ◽

Biological Tissues ◽

Soft Tissue Regeneration ◽

Soft Tissue Engineering ◽

Degradation Properties ◽

Enhance Cell Adhesion

AbstractComplex biological tissues are highly viscoelastic and dynamic. Efforts to repair or replace cartilage, tendon, muscle, and vasculature using materials that facilitate repair and regeneration have been ongoing for decades. However, materials that possess the mechanical, chemical, and resorption characteristics necessary to recapitulate these tissues have been difficult to mimic using synthetic resorbable biomaterials. Herein, we report a series of resorbable elastomer-like materials that are compositionally identical and possess varying ratios of cis:trans double bonds in the backbone. These features afford concomitant control over the mechanical and surface eroding degradation properties of these materials. We show the materials can be functionalized post-polymerization with bioactive species and enhance cell adhesion. Furthermore, an in vivo rat model demonstrates that degradation and resorption are dependent on succinate stoichiometry in the elastomers and the results show limited inflammation highlighting their potential for use in soft tissue regeneration and drug delivery.

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Modeling the Large Deformation and Microstructure Evolution of Nonwoven Polymer Fiber Networks

Journal of Applied Mechanics ◽

10.1115/1.4041677 ◽

2018 ◽

Vol 86 (1) ◽

Cited By ~ 6

Author(s):

Mang Zhang ◽

Yuli Chen ◽

Fu-pen Chiang ◽

Pelagia Irene Gouma ◽

Lifeng Wang

Keyword(s):

Mechanical Properties ◽

Aspect Ratio ◽

Mechanical Behavior ◽

Large Deformation ◽

Biological Tissues ◽

High Porosity ◽

Polymer Fiber ◽

Fiber Networks ◽

Fiber Aspect Ratio ◽

Network Microstructure

The electrospinning process enables the fabrication of randomly distributed nonwoven polymer fiber networks with high surface area and high porosity, making them ideal candidates for multifunctional materials. The mechanics of nonwoven networks has been well established for elastic deformations. However, the mechanical properties of the polymer fibrous networks with large deformation are largely unexplored, while understanding their elastic and plastic mechanical properties at different fiber volume fractions, fiber aspect ratio, and constituent material properties is essential in the design of various polymer fibrous networks. In this paper, a representative volume element (RVE) based finite element model with long fibers is developed to emulate the randomly distributed nonwoven fibrous network microstructure, enabling us to systematically investigate the mechanics and large deformation behavior of random nonwoven networks. The results show that the network volume fraction, the fiber aspect ratio, and the fiber curliness have significant influences on the effective stiffness, effective yield strength, and the postyield behavior of the resulting fiber mats under both tension and shear loads. This study reveals the relation between the macroscopic mechanical behavior and the local randomly distributed network microstructure deformation mechanism of the nonwoven fiber network. The model presented here can also be applied to capture the mechanical behavior of other complex nonwoven network systems, like carbon nanotube networks, biological tissues, and artificial engineering networks.

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Analysis of Stress and Strain to Determine the Pressure Changes in Tight-Fitting Garment

Autex Research Journal ◽

10.2478/aut-2019-0006 ◽

2020 ◽

Vol 20 (1) ◽

pp. 49-55

Author(s):

Nareerut Jariyapunya ◽

Blažena Musilová

Keyword(s):

Mechanical Properties ◽

Mathematical Models ◽

Initial Phase ◽

Circumferential Stress ◽

The Body ◽

Stress And Strain ◽

Laplace’S Law ◽

Pressure Changes ◽

The Relationship ◽

Laplace's Law

AbstractBased on the mechanical properties of stretch fabrics and Laplace’s law, the mathematical models have been developed enabling one to determine the values of the relationship between the fabric strain and the circumferential stress depending on pressure and diameter of the body. The results obtained refer to the values of the parameters assessed for the initial phase of their exploitation, which allow us to preliminarily predict the values of these parameters.

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Study on the Mechanical Properties of Red Clay under Drying-Wetting Cycles

Advances in Materials Science and Engineering ◽

10.1155/2021/8665167 ◽

2021 ◽

Vol 2021 ◽

pp. 1-16

Author(s):

Qi Yanli ◽

MingZhou Bai ◽

Hao Zhou ◽

Hai Shi ◽

Pengxiang Li ◽

...

Keyword(s):

Mechanical Properties ◽

Direct Shear Test ◽

Shear Test ◽

Strain Curve ◽

Stress And Strain ◽

Direct Shear ◽

Guangxi Province ◽

Red Clay ◽

Plastic Hardening ◽

The Relationship

To study the mechanical properties of red clay under repeated dry and wet cycle test conditions, in this paper, the disturbed red clay in an engineering area in Liuzhou, Guangxi Province, was taken as the research object. By artificially controlling different dry and wet cycles in the laboratory, a direct shear test and triaxial consolidation drainage test were carried out on the red clay samples after different dry and wet cycles. The stress-strain curve and change rule of corresponding c and φ values were obtained. The results showed that, in both the direct shear test and the triaxial test, the shear strength parameters of red clay decreased with an increase in the number of dry and wet cycles and the attenuation was most obvious during the first cycle. With an increase in the number of dry and wet cycles, the attenuation gradually decreased. The constitutive model of the deviatoric stress and strain curve of red clay under dry and wet cycles was a plastic-hardening type. By analyzing the variation in parameters in the P-H model, the relationship between c, φ, and the number of dry and wet cycles n was obtained. The results showed that the parameters had different degrees of attenuation with the action of dry and wet cycles. To explain the above rules, some samples under different drying-wetting cycles were selected for environmental electron microscope scanning, and appropriate assumptions were made based on the microstructure.

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Influence of structure and composition in the mechanical properties of textile polymeric fabrics

Polymers and Polymer Composites ◽

10.1177/0967391118823075 ◽

2019 ◽

Vol 27 (4) ◽

pp. 222-227

Author(s):

Thiago Felix dos Santos ◽

Caroliny Minely da Silva Santos ◽

Rubens Tavares da Fonseca ◽

Vinicius Silva dos Santos ◽

Mariana Guisdana Grosschopf ◽

...

Keyword(s):

Mechanical Properties ◽

Mechanical Behavior ◽

Mass Loss ◽

Technological Development ◽

Mechanical Analysis ◽

Synthetic Polymer ◽

Stress And Strain ◽

Textile Sector ◽

Higher Sensitivity

Knitting is a very important textile sector in the area of technological development and also for the economy. The knitted have special characteristics that allow their use in different situations. To use them with better use, it is important to know what these properties are and so apply them for a particular purpose. This work investigates several types of knitted 100% cotton and blend 67% cotton/33% polyester and evaluates its behavior when subjected to mechanical analysis (friction, abrasion, and traction) under the respective standards ASTM D 4970 adapted to ISO 12945-2 and ASTM D 5034. The obtained results show that, for the mechanical properties analyzed, the types of loops present in the structure and the composition of the knitted are fundamental factors for optimizing stress and strain as well as reducing mass loss and the propensity to pilling formation. The double piquet structures have a higher sensitivity to the tests, especially when we insert the polyester synthetic polymer that significantly alters the mechanical behavior.

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Development of Polypropylene/Polyethylene Terephthalate Microfibrillar Composites Filament to Support Waste Management

Polymers ◽

10.3390/polym13020233 ◽

2021 ◽

Vol 13 (2) ◽

pp. 233 ◽

Cited By ~ 1

Author(s):

Abdulhakim Almajid ◽

Rolf Walter ◽

Tim Kroos ◽

Harry Junaidi ◽

Martin Gurka ◽

...

Keyword(s):

Mechanical Properties ◽

Waste Management ◽

Mechanical Behavior ◽

Polyethylene Terephthalate ◽

Melt Temperature ◽

Chamber Temperature ◽

Microfibrillar Composites ◽

Stretching Ratio ◽

The Relationship ◽

Properties Of Composites

The concept of microfibrillar composites (MFCs) is adopted to produce composites of polyethylene terephthalate (PET) fiber-reinforced polypropylene (PP) materials. The two polymers were dry mixed with PET content ranging from 22 to 45 wt%. The PET has been used as a reinforcement to improve the mechanical properties of composites. The relationship between the morphology of the MFC structure and the mechanical behavior of the MFC filament was investigated. Analysis of the structure and mechanical behavior helped to understand the influence of the stretching ratio, extruder-melt temperature, stretching-chamber temperature, and filament speed.

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Finite-Element Analysis and Optimization for Gradient Porous Structure of Artificial Bone

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.271-272.922 ◽

2012 ◽

Vol 271-272 ◽

pp. 922-926 ◽

Cited By ~ 2

Author(s):

Yan Mei Qi ◽

Li Jun Yang ◽

Li Li Wang

Keyword(s):

Mechanical Properties ◽

Porous Structure ◽

Equivalent Stress ◽

Strain Analysis ◽

Equivalent Strain ◽

Stress And Strain ◽

Artificial Bone ◽

Element Analysis ◽

Maximum Equivalent Stress ◽

Ansys Workbench

The loading force of the artificial bone implanted into the human body and the flowing, growth and deposition of cells were influenced by the gradient porous structure. The software of ANSYS Workbench was used in the paper for the stress and strain analysis of the gradient porous structure of the established 3D artificial bone. The variation of the maximum equivalent stress and maximum equivalent strain and elastic modulus changed through the changing of the loading force and porosity. Basis on meeting the mechanical properties, the porosity was used as the index for the optimization of the porous structure of the artificial bone. And it also laid the foundation for the subsequent laser sintering.

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Mechanical Properties Evolution of Polydimethylsiloxane During Crosslinking Process

MRS Proceedings ◽

10.1557/proc-975-0975-dd06-07 ◽

2006 ◽

Vol 975 ◽

Cited By ~ 1

Author(s):

Yi Zhao ◽

Xin Zhang

Keyword(s):

Mechanical Properties ◽

Mechanical Behavior ◽

Measurement System ◽

Curing Agent ◽

Operational Parameters ◽

Crosslinking Process ◽

Sensing Applications ◽

Curvature Measurement ◽

The Relationship ◽

Mechanical Sensing

ABSTRACTThis paper reports mechanical properties evolution of polydimethylsiloxane (PDMS) during the crosslinking process. In this work, PDMS crosslinking was induced by mixing base prepolymer and curing agent at certain ratios. The liquid prepolymer was spun coated on a silicon wafer, and the curvature change of the wafer was measured continuously using a curvature measurement system. The relationship between the curvature change and typical mechanical properties was investigated using a bilayer model; and the evolution of the properties was derived, as a function of operational parameters. This work is expected to help better understanding of the crosslinking process and provide practical strategies for controlling the mechanical behavior of the resulting polymer structures, especially those for mechanical sensing applications.

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Crystal structure, hydrogen bonding, mechanical properties and Raman spectrum of the lead uranyl silicate monohydrate mineral kasolite

RSC Advances ◽

10.1039/c9ra02931a ◽

2019 ◽

Vol 9 (27) ◽

pp. 15323-15334 ◽

Cited By ~ 10

Author(s):

Francisco Colmenero ◽

Jakub Plášil ◽

Joaquín Cobos ◽

Jiří Sejkora ◽

Vicente Timón ◽

...

Keyword(s):

Crystal Structure ◽

Mechanical Properties ◽

Hydrogen Bonding ◽

Raman Spectrum ◽

Mechanical Behavior ◽

New Method ◽

Complex Crystal Structure ◽

Detailed Interpretation ◽

The Relationship ◽

Complex Crystal

A profound understanding of the relationship between the complex crystal structure of kasolite and its mechanical behavior is provided. A detailed interpretation of its Raman spectrum and a new method for band resolution are reported.

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Mechanical Characterization of Biological Tissue: Finite Element Modeling

ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology ◽

10.1115/nemb2010-13320 ◽

2010 ◽

Author(s):

Yue Xuan ◽

Wei Tong

Keyword(s):

Thin Film ◽

Mechanical Properties ◽

Finite Element ◽

Soft Tissue ◽

Contact Area ◽

Soft Tissues ◽

Surface Deformation ◽

Indentation Test ◽

Biological Tissues ◽

Test System

Indentation, in addition to the traditional tensile testing, has been widely used for evaluating mechanical properties of hard materials such as metals and bone as well as soft materials like polymer and soft tissues. However, it is difficult to measure the contact area and surface deformation in conventional indentation tests of soft tissue which will bring large errors to the evaluation of the material properties. Also the assumption of isotropic property limited the usage of indentation test in characterizing the nonlinear, anisotropic properties of soft tissue thin film. In this project, 2D and 3D finite element analyses has been carried out to predict hyperelastic material response under indentation and punch tests. A novel indentation test system was developed, which made the direct measurement of local deformation and contact area possible. The apparatus consists of a transparent indenter, a digital microscope, and a computer based control and data acquisition system. The proposed testing system and associated finite element analysis are used to characterize the mechanical properties of multiscale (bulk and thin film) biological tissues.

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