Vascularized Multi-Functional Materials and Structures

2008 ◽  
Vol 47-50 ◽  
pp. 511-514 ◽  
Author(s):  
Adrian Bejan ◽  
Sylvie Lorente
Keyword(s):  
Mechanical Strength ◽  
Smart Materials ◽  
Functional Materials ◽  
Constructal Theory ◽  
Self Healing ◽  
Length Scales ◽  
Embedded Grids ◽  
Volumetric Cooling ◽  
Parallel Microchannels ◽  
The Right

Here we draw attention to the development of smart materials with embedded vasculatures that provide multiple functionality: volumetric cooling, self-healing, mechanical strength, etc. Vascularization is achieved by using tree-shaped (dendritic) and grid-shaped flow architectures. As length scales become smaller, dendritic vascularization provides dramatically superior volumetric bathing and transport properties than the use of bundles of parallel microchannels. Embedded grids of channels provide substantially better volumetric bathing when the channels have multiple diameters that are selected optimally and put in the right places. Two novel dendritic architectures are proposed: trees matched canopy to canopy, and trees that alternate with upside down trees. Both have optimized length scales and layouts. Flow architectures are derived from principle, in accordance with constructal theory, not by mimicking nature.

Design With Constructal Theory: Vascularized Composites for Volumetric Cooling

2008 ◽  
Author(s):  
Sunwoo Kim ◽  
Sylvie Lorente ◽  
Adrian Bejan
Keyword(s):  
Smart Materials ◽  
Constructal Theory ◽  
Configuration Design ◽  
New Class ◽  
Developing Flow ◽  
Global Performance ◽  
Vascular Channels ◽  
Volumetric Cooling ◽  
The Relationship ◽  
Made In

Constructal theory complements the analysis of thermodynamic systems by focusing on the flow configuration of the system, and on the relationship between configuration (design) and global performance. The design progress made in this emerging field is reviewed in a new book [1]. In this paper we outline our progress on developing flow architectures for a new class of smart materials: composites with vascular channels that provide volumetric flowing (bathing) and cooling.

A glance on rare earth oxides: importance, reserves, demand, applications, critical uncertainties, global economy, and zeta potential characterization

2020 ◽  
Vol 05 ◽  
Author(s):  
Silas Santos ◽  
Orlando Rodrigues ◽  
Letícia Campos
Keyword(s):  
Rare Earth ◽  
Zeta Potential ◽  
Sample Preparation ◽  
Rare Earths ◽  
Smart Materials ◽  
Global Economy ◽  
Materials Science ◽  
Functional Materials ◽  
Rare Earth Oxides ◽  
Interparticle Forces

Background: Innovation mission in materials science requires new approaches to form functional materials, wherein the concept of its formation begins in nano/micro scale. Rare earth oxides with general form (RE2O3; RE from La to Lu, including Sc and Y) exhibit particular proprieties, being used in a vast field of applications with high technological content since agriculture to astronomy. Despite of their applicability, there is a lack of studies on surface chemistry of rare earth oxides. Zeta potential determination provides key parameters to form smart materials by controlling interparticle forces, as well as their evolution during processing. This paper reports a study on zeta potential with emphasis for rare earth oxide nanoparticles. A brief overview on rare earths, as well as zeta potential, including sample preparation, measurement parameters, and the most common mistakes during this evaluation are reported. Methods: A brief overview on rare earths, including zeta potential, and interparticle forces are presented. A practical study on zeta potential of rare earth oxides - RE2O3 (RE as Y, Dy, Tm, Eu, and Ce) in aqueous media is reported. Moreover, sample preparation, measurement parameters, and common mistakes during this evaluation are discussed. Results: Potential zeta values depend on particle characteristics such as size, shape, density, and surface area. Besides, preparation of samples which involves electrolyte concentration and time for homogenization of suspensions are extremely valuable to get suitable results. Conclusion: Zeta potential evaluation provides key parameters to produce smart materials seeing that interparticle forces can be controlled. Even though zeta potential characterization is mature, investigations on rare earth oxides are very scarce. Therefore, this innovative paper is a valuable contribution on this field.

scholarly journals Dynamic Nanohybrid-Polysaccharide Hydrogels for Soft Wearable Strain Sensing

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3574
Author(s):  
Pejman Heidarian ◽  
Hossein Yousefi ◽  
Akif Kaynak ◽  
Mariana Paulino ◽  
Saleh Gharaie ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Strain Sensors ◽  
Self Healing ◽  
Nano Materials ◽  
Strain Sensing ◽  
Ferric Ions ◽  
Research Activity ◽  
Adhesion Properties ◽  
High Mechanical Strength ◽  
The Moment

Electroconductive hydrogels with stimuli-free self-healing and self-recovery (SELF) properties and high mechanical strength for wearable strain sensors is an area of intensive research activity at the moment. Most electroconductive hydrogels, however, consist of static bonds for mechanical strength and dynamic bonds for SELF performance, presenting a challenge to improve both properties into one single hydrogel. An alternative strategy to successfully incorporate both properties into one system is via the use of stiff or rigid, yet dynamic nano-materials. In this work, a nano-hybrid modifier derived from nano-chitin coated with ferric ions and tannic acid (TA/Fe@ChNFs) is blended into a starch/polyvinyl alcohol/polyacrylic acid (St/PVA/PAA) hydrogel. It is hypothesized that the TA/Fe@ChNFs nanohybrid imparts both mechanical strength and stimuli-free SELF properties to the hydrogel via dynamic catecholato-metal coordination bonds. Additionally, the catechol groups of TA provide mussel-inspired adhesion properties to the hydrogel. Due to its electroconductivity, toughness, stimuli-free SELF properties, and self-adhesiveness, a prototype soft wearable strain sensor is created using this hydrogel and subsequently tested.

Self-healing Polymeric Hydrogels: Toward Multifunctional Soft Smart Materials

2021 ◽  
Author(s):  
Xiao-Ling Zuo ◽  
Shao-Fan Wang ◽  
Xiao-Xia Le ◽  
Wei Lu ◽  
Tao Chen
Keyword(s):  
Smart Materials ◽  
Self Healing ◽  
Polymeric Hydrogels

scholarly journals Strain- and field-induced anisotropy in hybrid elastomers with elongated filler nanoparticles

Soft Matter ◽  
2021 ◽  
Author(s):  
Julian Seifert ◽  
Damian Günzing ◽  
Samira Webers ◽  
Martin Dulle ◽  
Margarita Kruteva ◽  
...  
Keyword(s):  
Smart Materials ◽  
Functional Materials ◽  
Induced Anisotropy

The implementation of anisotropy to functional materials is a key step towards future smart materials. In this work, we evaluate the influence of preorientation and sample architecture on the strain-induced...

Non-covalent assembly of a super-tough, highly stretchable and environmentally adaptable self-healing material inspired by nacre

2021 ◽  
Vol 9 (36) ◽  
pp. 20737-20747
Author(s):  
Xiaobo Zhu ◽  
Wenru Zheng ◽  
Haichao Zhao ◽  
Liping Wang
Keyword(s):  
Mechanical Strength ◽  
Self Healing ◽  
Highly Stretchable

Inspired by nacre, a super-tough self-healing material with a reverse nacre structure and interwoven network was prepared, which solved the contradiction between fast self-healing ability and good mechanical strength of traditional PU materials.

scholarly journals Cell-free genetic devices confer autonomic and adaptive properties to hydrogels

2019 ◽  
Author(s):  
Colette J. Whitfield ◽  
Alice M. Banks ◽  
Gema Dura ◽  
John Love ◽  
Jonathan E. Fieldsend ◽  
...  
Keyword(s):  
Gene Expression ◽  
Protein Synthesis ◽  
Information Processing ◽  
Synthetic Biology ◽  
Smart Materials ◽  
Living Organism ◽  
Chemical Diversity ◽  
Biological Information ◽  
Self Healing ◽  
Wide Range

AbstractSmart materials are able to alter one or more of their properties in response to defined stimuli. Our ability to design and create such materials, however, does not match the diversity and specificity of responses seen within the biological domain. We propose that relocation of molecular phenomena from living cells into hydrogels can be used to confer smart functionality to materials. We establish that cell-free protein synthesis can be conducted in agarose hydrogels, that gene expression occurs throughout the material and that co-expression of genes is possible. We demonstrate that gene expression can be controlled transcriptionally (using in gel gene interactions) and translationally in response to small molecule and nucleic acid triggers. We use this system to design and build a genetic device that can alter the structural property of its chassis material in response to exogenous stimuli. Importantly, we establish that a wide range of hydrogels are appropriate chassis for cell-free synthetic biology, meaning a designer may alter both the genetic and hydrogel components according to the requirements of a given application. We probe the relationship between the physical structure of the gel and in gel protein synthesis and reveal that the material itself may act as a macromolecular crowder enhancing protein synthesis. Given the extensive range of genetically encoded information processing networks in the living kingdom and the structural and chemical diversity of hydrogels, this work establishes a model by which cell-free synthetic biology can be used to create autonomic and adaptive materials.Significance statementSmart materials have the ability to change one or more of their properties (e.g. structure, shape or function) in response to specific triggers. They have applications ranging from light-sensitive sunglasses and drug delivery systems to shape-memory alloys and self-healing coatings. The ability to programme such materials, however, is basic compared to the ability of a living organism to observe, understand and respond to its environment. Here we demonstrate the relocation of biological information processing systems from cells to materials. We achieved this by operating small, programmable genetic devices outside the confines of a living cell and inside hydrogel matrices. These results establish a method for developing materials functionally enhanced with molecular machinery from biological systems.

Corrective Solutions for the Shaft with Flange Used for Fixing the Blade on a 5 kW Wind Turbine to Withstand Extreme Weather Conditions

2014 ◽  
Vol 1029 ◽  
pp. 118-123
Author(s):  
Rodica Bădărău ◽  
Teodor Miloş ◽  
Ilare Bordeaşu ◽  
Adrian Bej
Keyword(s):  
Mechanical Strength ◽  
Wind Turbine ◽  
Weather Conditions ◽  
Extreme Weather ◽  
Original Solution ◽  
Root Area ◽  
Materials Used ◽  
Improved Design ◽  
The Right ◽  
Technical Solutions

The paper presents a case study on the original solution of a flange shaft as part of the root area of a 5 kW wind turbine blade. There were analyzed the causes that led to the shaft breakage under wind loadings in extreme weather conditions, and consequently technical solutions have been searched in order to improve the shaft design making it more reliable as mechanical strength at extreme wind loadings. The flange shaft is a welded subassembly that keeps the blades attached to the rotor hub. The first part of the paper consists in an analysis referring the loading status, the materials used for blade manufacturing, the identification of critical areas where the breaking was initiated and also the causes for which the materials assumed and specified in the technical design and manufacturing technology failed under loading at wind gusts of about 30 m/sec. Based on this preliminary analysis, the second part of the paper presents the technical solutions which were considered in reference to the materials and the improved design concept aiming to provide the right mechanical strength necessary to withstand specific wind loadings in extreme weather conditions.

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