Dielectric Elastomer Composites

Dielectric Elastomer Composites
Author: Morteza Hakimi Siboni
Publisher:
Total Pages: 596
Release: 2014
Genre:
ISBN:

Dielectric Elastomers (DEs) are an interesting class of active materials that can exhibit coupled electrical and mechanical behaviors, for example they can respond to an external electric field by changing their shape or size. This unique property is known as electrostriction, and makes such materials promising candidates for a wide range of practical applications, and therefore there is a need for the design of DEs with enhanced electromechanical couplings. In this work we investigate the possibility of enhancing the electrostriction by making composites consisting of one or more family of filler phases in a soft dielectric host. We use homogenization techniques to obtain estimates for the effective response of such DECs under general electrical and mechanical loading conditions. Next, we use the homogenization estimates developed in this work to investigate the effect of various microstructural parameters on the overall response of DECs. We also study failure of DECs as characterized by dielectric breakdown and/or the onset of material instabilities. Two types of material instabilities will be considered: Loss of Positive Definiteness (LPD) and Loss of Ellipticity (LE). Finally, we attempt an optimal design for the microstructure of DECs with enhanced electromechanical couplings, which are capable of achieving large electrostrictive strains before the failure. Our results show that composites consisting of a very small concentration of rigid circular fibers with vanishing contrast in the dielectric properties can achieve the largest electrostrictive strains before failure. Finally, we attempt to study DECs in the post-bifurcated deformation regime. This is important since after the composite loses strong ellipticity, the solution of the homogenization problem may bifurcate into a lower energy (with generally softer mechanical response) solution, which is different from the pre-bifurcated solutions. This raises the interesting possibility of operating DECs in their softer post-bifurcated deformation regimes to further increase the maximum achievable electrostrictive strains.

Dielectric Elastomers as Electromechanical Transducers

Dielectric Elastomers as Electromechanical Transducers
Author: Federico Carpi
Publisher: Elsevier
Total Pages: 344
Release: 2011-09-06
Genre: Technology & Engineering
ISBN: 0080557724

Dielectric Elastomers as Electromechanical Transducers provides a comprehensive and updated insight into dielectric elastomers; one of the most promising classes of polymer-based smart materials and technologies. This technology can be used in a very broad range of applications, from robotics and automation to the biomedical field. The need for improved transducer performance has resulted in considerable efforts towards the development of devices relying on materials with intrinsic transduction properties. These materials, often termed as "smart or "intelligent, include improved piezoelectrics and magnetostrictive or shape-memory materials. Emerging electromechanical transduction technologies, based on so-called ElectroActive Polymers (EAP), have gained considerable attention. EAP offer the potential for performance exceeding other smart materials, while retaining the cost and versatility inherent to polymer materials. Within the EAP family, "dielectric elastomers, are of particular interest as they show good overall performance, simplicity of structure and robustness. Dielectric elastomer transducers are rapidly emerging as high-performance "pseudo-muscular actuators, useful for different kinds of tasks. Further, in addition to actuation, dielectric elastomers have also been shown to offer unique possibilities for improved generator and sensing devices. Dielectric elastomer transduction is enabling an enormous range of new applications that were precluded to any other EAP or smart-material technology until recently. This book provides a comprehensive and updated insight into dielectric elastomer transduction, covering all its fundamental aspects. The book deals with transduction principles, basic materials properties, design of efficient device architectures, material and device modelling, along with applications. - Concise and comprehensive treatment for practitioners and academics - Guides the reader through the latest developments in electroactive-polymer-based technology - Designed for ease of use with sections on fundamentals, materials, devices, models and applications

Elastomer-Based Composite Materials

Elastomer-Based Composite Materials
Author: Nikolay Dishovsky
Publisher: CRC Press
Total Pages: 457
Release: 2018-05-15
Genre: Science
ISBN: 1351659987

Elastomer-Based Composite Materials: Mechanical, Dynamic, and Microwave Properties and Engineering Applications is focused on elastomer-based composite materials comprising different types of reinforcing fillers. The book provides an informative examination of the possibilities for broadening the engineering applications of elastomer composites through using various types of hybrid fillers, ferrites, and ceramics, and also examines their synthesis and characterization. It discusses new hybrid fillers that have been synthesized by different techniques, e.g. impregnation of different substrates (carbon black, conductive carbon black, activated carbons, etc.) with silica or magnetite. These new fillers have been thoroughly characterized by standard techniques and by up-to-date methods, such as energy dispersive X-ray spectroscopy in scanning transmission electron microscopy (STEM-EDX), atomic absorption spectroscopy (AAS), and inductively coupled plasma–optical emission spectroscopy (ICP-OES). The effect of those fillers upon the curing properties, mechanical and dynamic parameters, electrical conductivity, and dielectric and microwave characteristics of elastomer-based composites is discussed in detail in this volume. The book also covers the influence of various types of ceramics (SiC, B4C, and TiB2) and barium and strontium hexaferrites upon the aforementioned properties of rubber composites in conjunction with a view toward solutions for environmental problems caused by waste tires. The book shows that pyrolysis-cum-water vapor is a suitable and environmentally friendly method for the conversion of the waste green tires into useful carbon-silica hybrid fillers. The properties of elastomer-based composites comprising different types of nanostructures (fullerenes, carbon nanotubes, graphene nanoplatelets), modified activated carbons, and calcined kaolin are also discussed. Special attention is paid to composites with lower levels of zinc oxide. The volume provides an abundance of knowledge on the detailed characterization of these fillers and on the curing, mechanical, dynamic mechanical, and dielectric and microwave properties of the elastomeric composites. The book surveys the most recent research activities of the authors, which will make it a vital reference source for scientists in both the academic and industrial sectors, as well as for individuals who are interested in rubber materials. It will be very useful for students, especially PhD students, scientists, lecturers, and engineers working or doing research in the field of polymer materials science, elastomer-based composites and nanocomposites and their engineering applications in the production of microwave absorbers and electromagnetic waves shielding materials, materials for electronics devices and telecommunications.

Advances in Dielectric Elastomer Composites

Advances in Dielectric Elastomer Composites
Author: Masoud Asgari
Publisher:
Total Pages: 0
Release: 2025-01-30
Genre: Technology & Engineering
ISBN: 9781032945644

This is a comprehensive guide to dielectric elastomer composites (DECs), which play an integral role in new electromechanically active smart-material technologies. Introducing the basic concepts behind DECs, the book is accessible to readers at all levels. It demonstrates how to implement practical problem-solving methods through nonlinear continuum mechanics and also discusses fibre-reinforced anisotropic DE composites and the electromechanically coupled behaviour of anisotropic fibre-reinforced DEs. Using practical examples throughout, it proposes models which utilise the strain energy function, nonlinear electro-elasticity, and nonlinear continuum mechanics. It presents clear guidelines for creating practical nonlinear finite element code, and introduces the reader to hyperelasticity. The book will be an accessible reference guide for students, researchers and engineers in the field of mechanical engineering, bioengineering, materials science, aeronautics, and robotics.

Polymer Composites for Electrical Engineering

Polymer Composites for Electrical Engineering
Author: Xingyi Huang
Publisher: John Wiley & Sons
Total Pages: 452
Release: 2021-11-01
Genre: Technology & Engineering
ISBN: 1119719607

Explore the diverse electrical engineering application of polymer composite materials with this in-depth collection edited by leaders in the field Polymer Composites for Electrical Engineering delivers a comprehensive exploration of the fundamental principles, state-of-the-art research, and future challenges of polymer composites. Written from the perspective of electrical engineering applications, like electrical and thermal energy storage, high temperature applications, fire retardance, power cables, electric stress control, and others, the book covers all major application branches of these widely used materials. Rather than focus on polymer composite materials themselves, the distinguished editors have chosen to collect contributions from industry leaders in the area of real and practical electrical engineering applications of polymer composites. The books relevance will only increase as advanced polymer composites receive more attention and interest in the area of advanced electronic devices and electric power equipment. Unique amongst its peers, Polymer Composites for Electrical Engineering offers readers a collection of practical and insightful materials that will be of great interest to both academic and industrial audiences. Those resources include: A comprehensive discussion of glass fiber reinforced polymer composites for power equipment, including GIS, bushing, transformers, and more) Explorations of polymer composites for capacitors, outdoor insulation, electric stress control, power cable insulation, electrical and thermal energy storage, and high temperature applications A treatment of semi-conductive polymer composites for power cables In-depth analysis of fire-retardant polymer composites for electrical engineering An examination of polymer composite conductors Perfect for postgraduate students and researchers working in the fields of electrical, electronic, and polymer engineering, Polymer Composites for Electrical Engineering will also earn a place in the libraries of those working in the areas of composite materials, energy science and technology, and nanotechnology.

Electromechanical Coupling Behavior of Dielectric Elastomer Composites

Electromechanical Coupling Behavior of Dielectric Elastomer Composites
Author: Ryan Steven Scurlock
Publisher:
Total Pages: 92
Release: 2016
Genre:
ISBN:

Dielectric elastomers have gained substantial interest in the past few decades under research efforts aimed to improve electromechanical transducer technology. This material is often termed a “smart material” due to its intrinsic transduction properties, allowing the elastomer to deform in response to electric stimulation. High mechanical compliance, lightweight, low cost, and the ability to achieve enormous voltage induced strains make dielectric elastomers excellent candidates to serve as electromechanical transducers, both as high efficiency actuators and energy harvesters. This work is focused on increasing the transduction efficiency of dielectric elastomers, strengthening their potential effectiveness as a transducer. To enhance the electrostriction of the material, a composite concept is introduced where rigid conducting fibrous electrodes are embedded into the dielectric. A combined theoretical and numerical modeling framework is developed to analyze the electromechanical behavior of several different composite arrangements. In order to examine the large mechanical deformations of the elastomer, a finite deformation theory is required for the description of the material behavior. To describe the material free energy, a compressible Neo-Hookean model is utilized. The finite element method is used for the numerical solution technique to the boundary value problem.

Electroactive Polymer (EAP) Actuators as Artificial Muscles

Electroactive Polymer (EAP) Actuators as Artificial Muscles
Author: Yoseph Bar-Cohen
Publisher: SPIE Press
Total Pages: 790
Release: 2004
Genre: Artificial organs
ISBN: 9780819452979

Covers the field of EAP with attention to all aspects and full infrastructure, including the available materials, analytical models, processing techniques, and characterization methods. This second edition covers advances in EAP in electric EAP, electroactive polymer gels, ionomeric polymer-metal composites, and carbon nanotube actuators.