Preface

Abstract

New electromechanical transducers with high energy output, high strains, high mechanical compliance, lightweight, damage-tolerance and low cost can enable needed advances in a variety of applications, such as robotics, automation and biomedical devices. The perceived need for improved transducer performance, which has progressively emerged in the last few decades, has drawn considerable efforts for the development of devices relying on materials with intrinsic transduction properties. These materials, often termed " smart " or " intelligent " , include improved piezoelectrics and magnetostrictive or shape-memory materials. While these technologies have addressed niche applications and continue to make incremental improvements, newer emerging electromechanical transduction technologies, based on so-called electroactive polymers (EAP), have gained a considerable attention. EAP offer the potential for performance exceeding other smart materials, while retaining the cost and versatility inherent in polymer materials. EAP are currently being developed and significantly studied as possible " artificial muscles " , i.e. functional surrogates of natural muscles, aimed at mimicking performances of biological actuation machines.Within the EAP family, a specific class of materials, known as " dielectric elastomers " , is drawing particular interest at present, because of its already demonstrated good overall performance, as well as its simplicity of structure and robustness due to the use of stable and commercially available polymer materials. 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 technology was introduced during late 1990s, pioneered by SRI International. While encouraging results have already been achieved, dielectric elastomers are quite new and are still being explored extensively. Dielectric elastomer transduction is enabling an enormous range of new applications that were precluded by any other EAP or smart-material technology until a few years ago.With such a great potential, it is no surprise that research efforts focused on dielectric elastomers are growing rapidly. This is demonstrated by the increasing number of related publications in scientific journals, conferences and workshops, as well as the academic research projects and industrial contracts. Furthermore, while the technology is still new and growing, the technical maturity achieved so far has led to a new company that is focused exclusively on commercially exploiting the potential of dielectric elastomers. This company, Artificial Muscle, Inc., was founded in 2004.This book intends to provide a comprehensive and updated insight on dielectric elastomer transduction, by covering all its fundamental aspects. The book is organized in five main sections, dealing with transduction principle...

Multi-functional dielectric elastomer artificial muscles for soft and smart machines

“…In addition to providing muscle-like forces capable of lifting 10 N, their use has been demonstrated in prototype devices for dynamic hand splints, bi-directional tilters for positioning systems and lightweight flexible space-structures. 60 Contractile stack actuators can be used in small devices. The Schlaak group at TU Darmstadt have developed a three stage automated manufacturing process: mixing and spinning polymer components to produce a thin layer 10 lm thick, thermal curing of the polymer, and spraying-on of electrode above a masked substrate.…”

Dielectric Elastomer Based “Grippers” for Soft Robotics

“…[3,4] In the last decade or so, there has been considerable interest in using dielectric elastomer actuators as artificial muscles for soft-robotics since dielectric elastomers have similar mechanical properties as human skin, notably a low elastic modulus and a large strain capability, and their actuation can be controlled by the application of an electrical voltage. [5][6][7][8][9] The last simplifies the infrastructure necessary for their implementation, eliminating the need of air pumps or compressors and gas valves typically found in pneumatics actuators. Because of its simplicity in controls, dielectric elastomers could enable untethered operation of soft robots while maintaining the overall compliance of the structure.…”

Microfabrication and characterization of an array of dielectric elastomer actuators generating uniaxial strain to stretch individual cells

“…Since the electrostatic force scales as the inverse of the dielectric thickness, DEAs are excellent candidates for miniaturization. Most DEA devices to date have been at least cm-scale (e.g., arm-wrestling robots [3], or compact motors [4]; see [5] for a review) to meter-scale (e.g., for energy harvesting from waves [6] or for airships [7]). Yet, there is an increasing research activity on mm-scale devices, for instance for tactile displays [8,9] and interest in going to even smaller scales.…”