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1
Wang, Tiesheng, Meisam Farajollahi, Yeon Sik Choi, I.-Ting Lin, Jean E. Marshall, Noel M. Thompson, Sohini Kar-Narayan, John D. W. Madden y Stoyan K. Smoukov. "Electroactive polymers for sensing". Interface Focus 6, n.º 4 (6 de agosto de 2016): 20160026. http://dx.doi.org/10.1098/rsfs.2016.0026.
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Electromechanical coupling in electroactive polymers (EAPs) has been widely applied for actuation and is also being increasingly investigated for sensing chemical and mechanical stimuli. EAPs are a unique class of materials, with low-moduli high-strain capabilities and the ability to conform to surfaces of different shapes. These features make them attractive for applications such as wearable sensors and interfacing with soft tissues. Here, we review the major types of EAPs and their sensing mechanisms. These are divided into two classes depending on the main type of charge carrier: ionic EAPs (such as conducting polymers and ionic polymer–metal composites) and electronic EAPs (such as dielectric elastomers, liquid-crystal polymers and piezoelectric polymers). This review is intended to serve as an introduction to the mechanisms of these materials and as a first step in material selection for both researchers and designers of flexible/bendable devices, biocompatible sensors or even robotic tactile sensing units.
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Kanaan, Akel F., Ana C. Pinho y Ana P. Piedade. "Electroactive Polymers Obtained by Conventional and Non-Conventional Technologies". Polymers 13, n.º 16 (13 de agosto de 2021): 2713. http://dx.doi.org/10.3390/polym13162713.
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Electroactive polymers (EAPs), materials that present size/shape alteration in response to an electrical stimulus, are currently being explored regarding advanced smart devices, namely robotics, valves, soft actuators, artificial muscles, and electromechanical sensors. They are generally prepared through conventional techniques (e.g., solvent casting and free-radical polymerization). However, non-conventional processes such as those included in additive manufacturing (AM) are emerging as a novel approach to tune and enhance the electromechanical properties of EAPs to expand the scope of areas for this class of electro-responsive material. This review aims to summarize the published work (from the last five years) in developing EAPs either by conventional or non-conventional polymer processing approaches. The technology behind each processing technique is discussed as well as the main mechanism behind the electromechanical response. The most common polymer-based materials used in the design of current EAPs are reviewed. Therefore, the main conclusions and future trends regarding EAPs obtained by conventional and non-conventional technologies are also given.
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Rahman, Md Hafizur, Harmony Werth, Alexander Goldman, Yuki Hida, Court Diesner, Logan Lane y Pradeep L. Menezes. "Recent Progress on Electroactive Polymers: Synthesis, Properties and Applications". Ceramics 4, n.º 3 (20 de septiembre de 2021): 516–41. http://dx.doi.org/10.3390/ceramics4030038.
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Electroactive polymers (EAPs) are an advanced family of polymers that change their shape through electric stimulation and have been a point of interest since their inception. This unique functionality has helped EAPs to contribute to versatile fields, such as electrical, biomedical, and robotics, to name a few. Ionic EAPs have a significant advantage over electronic EAPs. For example, Ionic EAPs require a lower voltage to activate than electronic EAPs. On the other hand, electronic EAPs could generate a relatively larger actuation force. Therefore, efforts have been focused on improving both kinds to achieve superior properties. In this review, the synthesis routes of different EAP-based actuators and their properties are discussed. Moreover, their mechanical interactions have been investigated from a tribological perspective as all these EAPs undergo surface interactions. Such interactions could reduce their useful life and need significant research attention for enhancing their life. Recent advancements and numerous applications of EAPs in various sectors are also discussed in this review.
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Maksimkin, Aleksey V., Tarek Dayyoub, Dmitry V. Telyshev y Alexander Yu Gerasimenko. "Electroactive Polymer-Based Composites for Artificial Muscle-like Actuators: A Review". Nanomaterials 12, n.º 13 (1 de julio de 2022): 2272. http://dx.doi.org/10.3390/nano12132272.
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Unlike traditional actuators, such as piezoelectric ceramic or metallic actuators, polymer actuators are currently attracting more interest in biomedicine due to their unique properties, such as light weight, easy processing, biodegradability, fast response, large active strains, and good mechanical properties. They can be actuated under external stimuli, such as chemical (pH changes), electric, humidity, light, temperature, and magnetic field. Electroactive polymers (EAPs), called ‘artificial muscles’, can be activated by an electric stimulus, and fixed into a temporary shape. Restoring their permanent shape after the release of an electrical field, electroactive polymer is considered the most attractive actuator type because of its high suitability for prosthetics and soft robotics applications. However, robust control, modeling non-linear behavior, and scalable fabrication are considered the most critical challenges for applying the soft robotic systems in real conditions. Researchers from around the world investigate the scientific and engineering foundations of polymer actuators, especially the principles of their work, for the purpose of a better control of their capability and durability. The activation method of actuators and the realization of required mechanical properties are the main restrictions on using actuators in real applications. The latest highlights, operating principles, perspectives, and challenges of electroactive materials (EAPs) such as dielectric EAPs, ferroelectric polymers, electrostrictive graft elastomers, liquid crystal elastomers, ionic gels, and ionic polymer–metal composites are reviewed in this article.
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Xu, Wan Lu, Jian Bo Cao, Shi Ju E, Jia Ji, Jia Jiang, Jie Yu y Ruo Yang Wang. "Principle Experiment of Electroactive Polymer Wind-Driven Generator". Advanced Materials Research 305 (julio de 2011): 88–91. http://dx.doi.org/10.4028/www.scientific.net/amr.305.88.
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In order to alleviate the conflict among economic development, energy, and environment, the research and experimental analysis for the electroactive polymers (EAPs) was done. The EAPs were a new style of clean and efficient energy materials. The wind-driven generator installation based on EAPs was emulated and designed. The possibility of power generation was proved by the experiments.
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Bar-Cohen, Yoseph y Qiming Zhang. "Electroactive Polymer Actuators and Sensors". MRS Bulletin 33, n.º 3 (marzo de 2008): 173–81. http://dx.doi.org/10.1557/mrs2008.42.
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AbstractPolymers are highly attractive for their inherent properties of mechanical flexibility, light weight, and easy processing. In addition, some polymers exhibit large property changes in response to electrical stimulation, much beyond what is achievable by inorganic materials. This adds significant benefit to their potential applications.The focus of this issue of MRS Bulletin is on polymers that are electromechanically responsive, which are also known as electroactive polymers (EAPs). These polymers respond to electric field or current with strain and stress, and some of them also exhibit the reverse effect of converting mechanical motion to an electrical signal.There are many types of known polymers that respond electromechanically, and they can be divided according to their activation mechanism into field-activated and ionic EAPs. The articles in this issue cover the key material types used in these two groups, review the mechanisms that drive them, and provide examples of applications and current challenges. Recent advances in the development of these materials have led to improvement in the induced strain and force and the further application of EAPs as actuators for mimicking biologic systems and sensors. As described in this issue, the use of these actuators is enabling exciting applications that would be considered impossible otherwise.
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Olvera Bernal, Rigel Antonio, M. V. Uspenskaya y R. O. Olekhnovich. "Biopolymers and its application as electroactive polymers". Proceedings of the Voronezh State University of Engineering Technologies 83, n.º 1 (3 de junio de 2021): 270–77. http://dx.doi.org/10.20914/2310-1202-2021-1-270-277.
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Smart materials are a group of materials that exhibit the ability to change their composition or structure, their electrical and/or mechanical properties, or even their functions in response to an external stimulus such as heat, light, electricity, pressure, etc. Some of the advantages of these materials are: lightweight, flexibility, low cost of production, high energy density, fast response and compact size. One of the promises in the area of smart materials can be found in “smart polymer”. Polymers have many attractive characteristics, such as: lightweight, inexpensiveness, fractures tolerant, and pliable. Furthermore, they can be configured into almost any conceivable shape and their properties can be tailored according to the required needs. The capability of electroactive polymers (EAPs) to respond to electrical stimuli with a mechanical response, is attracting the attention of the scientific community from a wide range of disciplines. Biopolymers in recent decades have been studied as potential electroactive materials. These groups of polymers are extracted from a natural source; thus, they are eco-friendly, additionally they stand as a cheaper solution for the development of smart materials.The present manuscript will explore some of its applications as EAPs.
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Li, Yi, Mingfei Guo y Yanbiao Li. "Recent advances in plasticized PVC gels for soft actuators and devices: a review". Journal of Materials Chemistry C 7, n.º 42 (2019): 12991–3009. http://dx.doi.org/10.1039/c9tc04366g.
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Plasticized poly(vinyl chloride) (PVC) gels belong to a class of electroactive polymers (EAPs), which have the ability to realize bending motion, contractile motion, extended motion and crawling motion under electric stimulation.
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Hwang, Jiunn-Jer, Aamna Bibi, Yu-Ci Chen, Kun-Hao Luo, Hsiang-Yuan Huang y Jui-Ming Yeh. "Comparative Studies on Carbon Paste Electrode Modified with Electroactive Polyamic Acid and Corresponding Polyimide without/with Attached Sulfonated Group for Electrochemical Sensing of Ascorbic Acid". Polymers 14, n.º 17 (25 de agosto de 2022): 3487. http://dx.doi.org/10.3390/polym14173487.
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In this study, electroactive poly (amic acid) (EPAA) and corresponding polyimide (EPI) without or with a sulfonated group (i.e., S-EPAA, and S-EPI) were prepared and applied in electrochemical sensing of ascorbic acid (AA). The electroactive polymers (EAPs) containing EPAA/EPI and S-EPAA/S-EPI were synthesized by using an amine-capped aniline trimer (ACAT) and sulfonated amine-capped aniline trimer (S-ACAT) as an electroactive segment that controlled the redox capability and influenced the degree of sensitivity of the EAPs towards AA. Characterization of the as-prepared EAPs was identified by FTIR spectra. The redox capability of the EAPs was investigated by electrochemical cyclic voltammetric studies. It should be noted that the redox capability of the EAPs was found to show the following trend: S-EPAA > S-EPI > EPAA > EPI. For the electrochemical sensing studies, a sensor constructed from an S-EPAA-modified carbon paste electrode (CPE) demonstrated 2-fold, 1.27-fold, and 1.35-fold higher electro-catalytic activity towards the oxidation of AA, compared to those constructed using a bare CPE, S-EPI-, and EPI/EPAA-modified CPE, respectively. The higher redox capability of S-EPAA-modified CPE exhibited a good electrochemical response towards AA at a low oxidative potential, with good stability and selectivity. Moreover, an electrochemical sensor constructed from S-EPAA-modified CPE was found to reveal better selectivity for a tertiary mixture of AA/DA/UA, as compared to that of EPI-modified, EPAA-modified and S-EPI-modified CPE, based on a series of differential pulse voltammograms.
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Bass, Patrick S., Lin Zhang y Z. Y. Cheng. "Time-dependence of the electromechanical bending actuation observed in ionic-electroactive polymers". Journal of Advanced Dielectrics 07, n.º 02 (abril de 2017): 1720002. http://dx.doi.org/10.1142/s2010135x17200028.
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The characteristics of the electromechanical response observed in an ionic-electroactive polymer (i-EAP) are represented by the time ([Formula: see text]) dependence of its bending actuation ([Formula: see text]). The electromechanical response of a typical i-EAP — poly(ethylene oxide) (PEO) doped with lithium perchlorate (LP) — is studied. The shortcomings of all existing models describing the electromechanical response obtained in i-EAPs are discussed. A more reasonable model: [Formula: see text] is introduced to characterize this time dependence for all i-EAPs. The advantages and correctness of this model are confirmed using results obtained in PEO-LP actuators with different LP contents and at different temperatures. The applicability and universality of this model are validated using the reported results obtained from two different i-EAPs: one is Flemion and the other is polypyrrole actuators.
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Liu, Zhi Yun, Shi Ju E y Jian Bo Cao. "Research on Vibration Energy Recovery of Base on EAPs". Advanced Materials Research 511 (abril de 2012): 129–33. http://dx.doi.org/10.4028/www.scientific.net/amr.511.129.
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In order to promote the efficient recovery of the vibration energy, to achieve the purpose that energy of vibration can be converted to electrical energy and implement the vibration energy recovery, the electroactive polymers (EAPs) were discussed and studied in this paper. The vibration power generation mechanism of EAPs and vibration system were theoretical analysed, a nonlinear technology (synchronized switch harvesting with inductor) was used in process of energy recovery. The experimental results showed that EAPs had good effect of the vibration energy conversion and nonlinear technology was more efficient than conventional technology in energy recovery.
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Shariff, Mohd Halim Bin Mohd, Jose Merodio, Roger Bustamante y Aymen Laadhari. "A Non-Second-Gradient Model for Nonlinear Electroelastic Bodies with Fibre Stiffness". Symmetry 15, n.º 5 (11 de mayo de 2023): 1065. http://dx.doi.org/10.3390/sym15051065.
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The study of the mechanical behaviour of fibre-reinforced electroactive polymers (EAPs) with bending stiffness is beneficial in engineering for mechanical design and problem solving. However, constitutive models of fibre-reinforced EAPs with fibre bending stiffness do not exist in the literature. Hence, to enhance the understanding of the mechanical behaviour of fibre-reinforced EAPs with fibre bending stiffness, the development of a relevant constitutive equation is paramount. In this paper, we develop a constitutive equation for a nonlinear nonpolar EAP, reinforced by embedded fibres, in which the elastic resistance of the fibres to bending is modelled via the classical branches of continuum mechanics without using the second gradient theory, which assumes the existence of contact torques. In view of this, the proposed model is simple and somewhat more realistic, in the sense that contact torques do not exist in nonpolar EAPs.
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Gu, Jing, Zixing Zhou, Yang Xie, Xiaobin Zhu, Guoyou Huang y Zuoqi Zhang. "A Microactuator Array Based on Ionic Electroactive Artificial Muscles for Cell Mechanical Stimulation". Biomimetics 9, n.º 5 (8 de mayo de 2024): 281. http://dx.doi.org/10.3390/biomimetics9050281.
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Mechanical stimulation is prevalent within organisms, and appropriate regulation of such stimulation can significantly enhance cellular functions. Consequently, the in vitro construction and simulation of mechanical stimulation have emerged as a research hotspot in biomechanics. In recent years, a class of artificial muscles named electroactive polymers (EAPs), especially ionic EAPs, have shown promising applications in biomechanics. While several techniques utilizing ionic EAPs for cell mechanical stimulation have been reported, further research is needed to advance and enhance their practical applications. Here, we prepared a microactuator array based on ionic EAP artificial muscles for cell mechanical stimulation. As a preliminary effort, we created a 5 × 5 microactuator array on a supporting membrane by employing laser cutting. We evaluated the electro-actuation performance of the microactuators through experimental testing and numerical simulations, affirming the potential use of the microactuator array for cell mechanical stimulation. The devised approach could inspire innovative design concepts in the development of miniaturized intelligent electronic devices, not only in biomechanics and biomimetics but also in other related fields.
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Prasad Verma, Rajendra y Sharad Chandra Srivastava. "Discussion on an Overview of Graphene Nanocomposites and Dielectric Elastomers". Journal of Futuristic Sciences and Applications 1, n.º 2 (2018): 1–16. http://dx.doi.org/10.51976/jfsa.121801.
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This article examines the most current advancements in dielectric elastomer actuator technology. The adaptability of these actuators makes them helpful in a wide range of situations. Dielectric elastomers, a kind of electroactive polymer, undergo a transformation when subjected to an electric field. When compared to piezoelectric materials, shape memory alloys, ionic polymer metallic materials, and form memory alloys, EAPs' applicability for the design of a broad range of sensors, actuators, and biomedical equipment is better. Because EAPs are able to preserve their original shape even after being distorted, this is why they are so effective. Since EAPs are light, adaptable, simple to manufacture, economically viable, and compatible with surfaces and geometries of varying complexity, this is the case. Shape-memory alloys and materials with piezoelectric characteristics are also included. The working electric field is rather intense, and the dielectric constant is quite low, making this material challenging to deal with. This is the most significant stumbling block in the process of dealing with this particular substance. One way to deal with this problem is to use filler materials that are extremely conductive, such as graphene oxide (GO), reduced graphene oxide (RGO), or functionalized graphene oxide. Functionalized graphene oxide and reduced graphene oxide are other possible techniques. In addition to functionalized graphene oxide and reduced graphene oxide, there are two more ways that might be used. A lot of choices are now at your disposal, including this one. Actuators that rely on this material may now be built since EAPs composites have been created with a typical low operating voltage (on the request for 50 V/m). To put it another way, we can now design actuators that are reliant on this material. These materials are used as actuators in many different types of control, adaptable, and automated systems, including many different academic areas, such as science, electromechanics, and others. [For instance:] There are several examples of this, such as: [As an illustration:] ... [Here's a great example of] There are a number of issues related with the usage of electroactive polymers (EAPs) in this study, which was focused on the operating principle and actuation mechanism.
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Bass, Patrick, Lin Zhang, Maobing Tu y ZhongYang Cheng. "Enhancement of Biodegradable Poly(Ethylene Oxide) Ionic–Polymer Metallic Composite Actuators with Nanocrystalline Cellulose Fillers". Actuators 7, n.º 4 (17 de octubre de 2018): 72. http://dx.doi.org/10.3390/act7040072.
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Biodegradable ionic polymer metallic composite (IPMC) electroactive polymers (EAPs) were fabricated using poly(ethylene oxide) (PEO) with various concentrations of lithium perchlorate. Nanocrystalline cellulose (NCC) rods created from a sulfuric acid hydrolysis process were added at various concentrations to increase the EAPs’ elastic modulus and improve their electromechanical properties. The electromechanical actuation was studied. PEONCC composites were created from combining a 35-mg/mL aqueous NCC suspension with an aqueous, PEO solution at varying vol.%. Due to an imparted space charge from the hydrolysis process, composites with an added 1.5 vol.% of NCC suspension exhibited an electromechanical tip displacement, strain, and elastic modulus that was 40.7%, 33.4% and 20.1% higher, respectively, than those for PEO IPMCs without NCC. This performance represented an increase of 300% in the energy density of these samples. However, the electromechanical response decreased when the NCC content was high. NCC without the space charge were also tested to verify the analysis. Additionally, the development of new relationships for modeling and evaluating the time-dependent instantaneous tip angular velocity and acceleration was discussed and applied to these IPMCs.
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Choi, Hyouk Ryeol, Kwang Mok Jung, Ja Choon Koo, Jae Do Nam, Young Kwan Lee y Mi Suk Cho. "Electrostatically Driven Soft Polymer Actuator Based on Dielectric Elastomer". Key Engineering Materials 297-300 (noviembre de 2005): 622–27. http://dx.doi.org/10.4028/www.scientific.net/kem.297-300.622.
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ElectroActive Polymers (EAPs) are emerging as new actuating means replacing the existing technologies such as piezoelectric, electrostatic, SMA etc. The dielectric elastomer actuator is regarded as the one of the most practically applicable actuators in the near future among the EAPs. In this paper, we introduce a new material capable of being employed as the dielectric elastomer actuator. The proposed material, which is a kind of the synthetic rubber, produces larger deformation as well as higher enegy efficiency, since it has a much higher dielectric constant compared to the previous ones. Beginning with the method of material synthesis, we give the description of its basic material properties by comparing with those of the existing materials for the dielectric elastomers. Also, the advantages of the proposed material as the actuating means are discussed with the several results of the experiments.
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Kumar, Ponnusamy Senthil y P. R. Yaashikaa. "Ionic Polymer Metal Composites". Diffusion Foundations 23 (agosto de 2019): 64–74. http://dx.doi.org/10.4028/www.scientific.net/df.23.64.
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Electroactive polymers, or EAPs, are polymers that show an adjustment fit as a fiddle when invigorated by an electric field. Ionic polymer metal composites (IPMCs) are electro-dynamic polymers with great electromechanical coupling properties. They are proficient applicants in many progressed innovative applications, for example, actuators, artificial muscles, biomimetic sensors, and so forth. Type of membrane and electrodes determines the morphology and structure of IPMCs. IPMCs can be prepared using physical loading, chemical deposition and electroplating methods. The assembling of anodes for IPMCs is exceptionally basic in their electromechanical coupling. Optimization of force, determination of cations and molecule size dispersal inside the IPMC structure, and so on are the different components, which decides their proficiency. An ionic polymer-metal composite (IPMC) comprising of a thin Nafion sheet, platinum plated on the two side faces, experiences extensive twisting movement when an electric field is connected over its thickness. Then again, a voltage is created over its appearances when it is all of a sudden bends. IPMCs are best known for their proving advantages such as biocompactible, low activating voltage and more power efficiency
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Choi, Hyouk Ryeol, Kwang Mok Jung, Min Young Jung, Ja Choon Koo, Jae Do Nam y Young Kwan Lee. "Development of a Soft Linear Motion Actuator Using Synthetic Rubber". Key Engineering Materials 306-308 (marzo de 2006): 1193–98. http://dx.doi.org/10.4028/www.scientific.net/kem.306-308.1193.
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As ElectroActive Polymers (EAPs) attract keen attentions from various engineering fields, they have been proven more beneficial over the traditional electromagnetic transducers. In the present paper, a new polymeric material that could be adopted for a dielectric elastomer actuator is introduced. The proposed synthetic rubber produces larger deformation at higher energy efficiency compared to previously known dielectric elastomers. A method for the material synthesis and a set of comparative testing of the material to the existing material are to be mentioned in the present work. In addition, benefits of actuators made with the proposed material are discussed.
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Neubauer, Justin, Zakai J. Olsen, Zachary Frank, Taeseon Hwang y Kwang J. Kim. "A study of mechanoelectrical transduction behavior in polyvinyl chloride (PVC) gel as smart sensors". Smart Materials and Structures 31, n.º 1 (22 de noviembre de 2021): 015010. http://dx.doi.org/10.1088/1361-665x/ac358f.
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Abstract Polyvinyl chloride (PVC) gels are soft electroactive polymers (EAPs) being researched for soft robotic applications. Sensing properties of these EAPs have not been investigated in detail in regard to fundamental mechanoelectrical transduction behavior, but this smart material has been shown to exhibit a detectable response to external stimuli. This study shows PVC gels to be an extremely sensitive material when undergoing mechanoelectrical transduction and explores some response dependencies and proposes a theoretical framework for mechanoelectrical transduction within the gel. The work presented here also uncovers a very interesting phenomena under extremely low compressive loads during the initial contact with the gel. This phenomenon is attributed to a surface tension creeping motion onto the loading surface with an accompanying polarity inversion in the sensing signal relative to fully loaded gels in compression. Experimental work on hysteresis was also completed showing very little memory in steady state mechanoelectrical response to repeated stepped loading cycles. This study demonstrates the mechanoelectric ability of PVC gels to perform in sensing experiments and acts as a fundamental framework to further broaden the applications of PVC gel sensors.
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Liu, Xue Jing, Gong Zhang, Yong Quan Wang y Shu Hai Jia. "Manufacture and Experimental Investigation of a Multi-Layer Generator Based on Dielectric Elastomer". Advanced Materials Research 960-961 (junio de 2014): 1336–41. http://dx.doi.org/10.4028/www.scientific.net/amr.960-961.1336.
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As a member of Electroactive Polymers (EAPs), dielectric elastomer (DE) has shown considerable potential for energy harvesting applications. After the basic principle of DE energy harvesting is studied, a multi-layer DE generator using VHB 4910 (3M, USA) is specially designed and fabricated. Then, an improved energy harvesting circuit is designed to make use of harvested electrical energy. Finally, energy harvesting experiments are implemented under the constant charge (open-circuit) condition and the results prove that the multi-layer DE generator fabricated can produce enough energy to constantly drive a light emitting diode. The harvested electrical energy has good consistent with generated electrical energy and the maximum energy harvesting efficiency ηh can reach 89%.
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Bar-Cohen, Y. "Artificial muscles based on electroactive polymers as an enabling tool in biomimetics". Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 221, n.º 10 (30 de septiembre de 2007): 1149–56. http://dx.doi.org/10.1243/09544062jmes510.
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Evolution has resolved many of nature's challenges leading to working and lasting solutions that employ principles of physics, chemistry, mechanical engineering, materials science, and many other fields of science and engineering. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems, and many other benefits. Some of the technologies that have emerged include artificial intelligence, artificial vision, and artificial muscles, where the latter is the moniker for electroactive polymers (EAPs). To take advantage of these materials and make them practical actuators, efforts are made worldwide to develop capabilities that are critical to the field infrastructure. Researchers are developing analytical model and comprehensive understanding of EAP materials response mechanism as well as effective processing and characterization techniques. The field is still in its emerging state and robust materials are still not readily available; however, in recent years, significant progress has been made and commercial products have already started to appear. In the current paper, the state-of-the-art and challenges to artificial muscles as well as their potential application to biomimetic mechanisms and devices are described and discussed.
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Zhang, Chenghong, Chengguang Zhang, Guangping Tian y Xun Gu. "Electromechanical Coupling Model for Ionic Liquid Gel Soft Actuators". Applied Bionics and Biomechanics 2024 (13 de febrero de 2024): 1–12. http://dx.doi.org/10.1155/2024/8369544.
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A soft robot is composed of soft materials, which exhibit continuous deformation and driving structure integration and can arbitrarily change shapes and sizes over wide ranges. It shows strong adaptability to unstructured environments and has broad application prospects in military reconnaissance, medical rescues, agricultural production, etc. Soft robots based on ionic electroactive polymers (EAPs) have low-driving voltages, large-actuation displacements, fast responses, light weights, and low powers and have become a hot research field of bionic robots. Ionic liquid gels (ILGs) are new ionic EAPs. In this study, a new soft actuator was designed based on an ILG, and the electromechanical coupling model of an ILG soft actuator was studied in detail. Based on the system transfer function method, a mechatronic coupling model for the soft actuator was developed. According to the material characteristics and current response law of the ILG-containing EAP, an equivalent circuit model was used to describe transfer of the output current and input voltage. Based on the equivalent transformer model for ionic polymer–metal composite (IPMC) actuators proposed by Claudia Bonomo, the electromechanical coupling equation and a driving equation of the ILG soft actuator were established. The least-squares method was used with the coupling model of an ILG soft actuator to identify the system parameters for the model, and the effects of the structural parameters on the end displacement and driving force of the soft actuator were analyzed.
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Lam, Tu-Ngoc, Chia-Yin Ma, Po-Han Hsiao, Wen-Ching Ko, Yi-Jen Huang, Soo-Yeol Lee, Jayant Jain y E.-Wen Huang. "Tunable Mechanical and Electrical Properties of Coaxial Electrospun Composite Nanofibers of P(VDF-TrFE) and P(VDF-TrFE-CTFE)". International Journal of Molecular Sciences 22, n.º 9 (28 de abril de 2021): 4639. http://dx.doi.org/10.3390/ijms22094639.
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The coaxial core/shell composite electrospun nanofibers consisting of relaxor ferroelectric P(VDF-TrFE-CTFE) and ferroelectric P(VDF-TrFE) polymers are successfully tailored towards superior structural, mechanical, and electrical properties over the individual polymers. The core/shell-TrFE/CTFE membrane discloses a more prominent mechanical anisotropy between the revolving direction (RD) and cross direction (CD) associated with a higher tensile modulus of 26.9 MPa and good strength-ductility balance, beneficial from a better degree of nanofiber alignment, the increased density, and C-F bonding. The interfacial coupling between the terpolymer P(VDF-TrFE-CTFE) and copolymer P(VDF-TrFE) is responsible for comparable full-frequency dielectric responses between the core/shell-TrFE/CTFE and pristine terpolymer. Moreover, an impressive piezoelectric coefficient up to 50.5 pm/V is achieved in the core/shell-TrFE/CTFE composite structure. Our findings corroborate the promising approach of coaxial electrospinning in efficiently tuning mechanical and electrical performances of the electrospun core/shell composite nanofiber membranes-based electroactive polymers (EAPs) actuators as artificial muscle implants.
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Wang, Hua Ming, Hua An Luo y Bin Yang. "Implementation and Control of a Rotary Manipulator Driven by Soft Dielectric Electroactive Polymer". Applied Mechanics and Materials 461 (noviembre de 2013): 352–57. http://dx.doi.org/10.4028/www.scientific.net/amm.461.352.
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Dielectric Electroactive Polymers (EAPs) are closest to natural muscles in terms of strain, energy density, efficiency and speed. A 2-DOF (Degree of Freedom) rotary manipulator driven by soft dielectric EAP is designed based on the biological agonist–antagonist configuration. Compact rolled actuators are chosen and implemented to drive the manipulator. To avoid the complicated solving of nonlinear differential equations, electromechanical characteristics of actuators are obtained by measuring their force behavior under different voltages and lengths. A CMAC (Cerebellar model articulation controller) neural network-based closed loop controller is developed to implement the position control of the manipulator and is evaluated by tracking a circle. According to the force analysis of the manipulator, forces of antagonistic actuators are determined by force decomposition to produce the desired force output, and then the voltages for actuators at certain lengths can be calculated through measured electromechanical characteristics. Experiment shows the measured force agrees well with the desired force. Due to the advantages of dielectric EAP, the manipulator has application prospects in areas of rehabilitation, force feedback or flexible manipulation without damage.
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Henke, Markus, Jörg Sorber y Gerald Gerlach. "EAP-Actuators with Improved Actuation Capabilities for Construction Elements with Controllable Stiffness". Advances in Science and Technology 79 (septiembre de 2012): 75–80. http://dx.doi.org/10.4028/www.scientific.net/ast.79.75.
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This contribution considers an actuator based on Electroactive Polymers (EAPs) which is used for constructional elements with controllable stiffness. The actuator consists of a Danfoss PolyPower EAP-foil and a supporting structure which applies the necessary pre-straining force to the foil. Usually, such structures have a constant spring stiffness which strongly limits the actuation range. The novel actuator shows a highly nonlinear spring stiffness for pre-straining the foil. Therefore, the pre-straining force is nearly constant all over the entire actuation range. This behavior can be used to double the possible actuation range. Such structures are suitable to be used in construction elements with variable stiffness. The contribution shows the basic function of this actuator and its capabilities for the application in new smart, self-sensing and self-controlling composite materials for lightweight constructions. The theoretical background of highly nonlinear spring stiffness is discussed and transferred to the developed structures. The theoretical calculations are based on analytic calculations and finite element analyses and are verified by experimental set-ups consisting of different actuators both with constant and highly nonlinear pre-straining spring constant.
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Serdas, Serdar, Joachim Bluhm y Jörg Schröder. "A thermodynamical consistent model for modeling of ionic electroactive polymers (EAPs) within the framework of the Theory of Porous Media". PAMM 16, n.º 1 (octubre de 2016): 485–86. http://dx.doi.org/10.1002/pamm.201610231.
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Pfeil, Sascha, Alice Mieting, Rebecca Grün, Konrad Katzer, Johannes Mersch, Cornelia Breitkopf, Martina Zimmermann y Gerald Gerlach. "Underwater Bending Actuator Based on Integrated Anisotropic Textile Materials and a Conductive Hydrogel Electrode". Actuators 10, n.º 10 (14 de octubre de 2021): 270. http://dx.doi.org/10.3390/act10100270.
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Electroactive polymers (EAPs), especially dielectric elastomer actuators (DEAs), belong to a very promising and emerging class of functional materials. While DEAs are mostly utilized to rely on carbon-based electrodes, there are certain shortcomings of the use of carbon electrodes in the field of soft robotics. In this work we present a fish-like bending structure to serve as possible propulsion element, completely avoiding carbon-based electrodes. The presented robot is moving under water, using a particularly tailored conductive hydrogel as inner electrode and a highly anisotropic textile material to manipulate the bending behavior of the robot. The charge separation to drive two DEAs on the outsides of the robot is provided by the conductive hydrogel while the surrounding water serves as counter electrode. To characterize the hydrogel, tensile tests and impedance spectroscopy are used as measurement methods of choice. The performance of the robot was evaluated using a digital image correlation (DIC) measurement for its bending deflections under water. The developed fish-like robot was able to perform a dynamic bending movement, based on a tri-stable actuator setup. The performed measurements underpin the sufficient characteristics for an underwater application of conductive hydrogel electrodes as well as the applicability of the robotic concept for under water actuations.
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Corbaci, Mert, Wayne Walter y Kathleen Lamkin-Kennard. "Implementation of Soft-Lithography Techniques for Fabrication of Bio-Inspired Multi-Layer Dielectric Elastomer Actuators with Interdigitated Mechanically Compliant Electrodes". Actuators 7, n.º 4 (21 de octubre de 2018): 73. http://dx.doi.org/10.3390/act7040073.
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Advancements in software engineering have enabled the robotics industry to transition from the use of giant industrial robots to more friendly humanoid robots. Soft robotics is one of the key elements needed to advance the transition process by providing a safer way for robots to interact with the environment. Electroactive polymers (EAPs) are one of the best candidate materials for the next generation of soft robotic actuators and artificial muscles. Lightweight dielectric elastomer actuators (DEAs) provide optimal properties such as high elasticity, rapid response rates, mechanical robustness and compliance. However, for DEAs to become widely used as artificial muscles or soft actuators, there are current limitations, such as high actuation voltage requirements, control of actuation direction, and scaling, that need to be addressed. The authors’ approach to overcome the drawbacks of conventional DEAs is inspired by the natural skeletal muscles. Instead of fabricating a large DEA device, smaller sub-units can be fabricated and bundled together to form larger actuators, similar to the way myofibrils form myocytes in skeletal muscles. The current study presents a novel fabrication approach, utilizing soft lithography and other microfabrication techniques, to allow fabrication of multilayer stacked DEA structures, composed of hundreds of micro-sized DEA units.
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Seo, Jin-Sung, Do-Hyeon Kim, Heon-Seob Jung, Ho-Dong Kim, Jaewon Choi, Minjae Kim, Sung-Hyeon Baeck y Sang-Eun Shim. "Effect of the Particle Size and Layer Thickness of GNP Fillers on the Dielectric Properties and Actuated Strain of GNP–PDMS Composites". Polymers 14, n.º 18 (13 de septiembre de 2022): 3824. http://dx.doi.org/10.3390/polym14183824.
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Dielectric elastomer actuators (DEAs), a type of electroactive polymers (EAPs), are smart materials that are used in various fields such as artificial muscles and biomimetic robots. In this study, graphene nanoplatelets (GNPs), which are conductive carbon fillers, were added to a widely used DEA, namely, polydimethylsiloxane (PDMS), to improve its low actuated strain. Four grades of GNPs were used: H5, H25, M5, and M25 (here, the number following the letter indicates the average particle size of the GNPs in μm). The average layer thickness of the H grade is 13–14 nm and that of the M grade is 5–7 nm. PDMS composites were prepared by adding 0.5, 1, 2, and 3 wt% of each GNP, following which the mechanical properties, dielectric properties, and actuated strain of the composites were measured. The mechanical properties were found to increase as the particle size increased. Regarding the dielectric characteristics, it was found that the higher the aspect ratio of the filler, the easier the formation of a micro-capacitor network in the composite—this led to an increase in the dielectric constant. In addition, the higher amounts of GNPs in the composites also led to an increase in the dielectric constant. For the actuated strain analysis, the electromechanical sensitivity was calculated using the ratio of the dielectric constant to the Young’s modulus, which is proportional to the strain. However, it was found that when the loss tangent was high, the performance of the actuated strain decreased owing to the conversion of electric energy into thermal energy and leakage current loss. As a result, the highest actuated strain was exhibited by the M25 composite, with an actuated strain value of 3.01% measured at a low electric field (<4 kV/mm). In conclusion, we proved that the GNP–PDMS composites with a thin layer and large particle size exhibited high deformation.
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Frostig, Y. "On wrinkling of a sandwich panel with a compliant core and self-equilibrated loads". Journal of Sandwich Structures & Materials 13, n.º 6 (noviembre de 2011): 663–79. http://dx.doi.org/10.1177/1099636211419131.
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The nonlinear response of a unidirectional sandwich panel that is associated with wrinkling of the face sheets, due to a self-equilibrated loading scheme is presented. This loading scheme may be a results of a manufacturing process where the core is tensioned first and the sandwich panel is formed through bonding of the face sheets to the tensioned core while wrinkling occurs as a result of the release of the tensile force of the core, i.e. similar to the manufacturing of electroactive polymers (EAPs) [Wantanaba et al. (2002)] or due to prestressing of the core which is associated with the pre-strain the edge of the core only. These self-equilibrated loads yield compression in the face sheets as well as in the core which may be associated with loss of stability as a result of overall buckling of the entire panel or wrinkling of the face sheets. Thus, for such loading scheme the longitudinal rigidity of the core must be considered although it is small as compared with that of the face sheets. The governing equations along with the appropriate boundary conditions are derived through the introduction of longitudinal normal stresses in the core along with high-order distribution functions for the displacements through its depth. The mathematical formulation is based on variational principles along with moderate type of deformations for the kinematic relations. The results of the various structural quantities in the form of curves along the panel, equilibrium curves and deformed shapes for a particular sandwich panel are presented. The study discusses the effects of the transfer of the compressive load from the core to the face sheets, either directly through an edge beam or without it. Conclusions are drawn and presented.
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Qu, Liangti, Qiang Peng, Liming Dai, Geoffrey M. Spinks, Gordon G. Wallace y Ray H. Baughman. "Carbon Nanotube Electroactive Polymer Materials: Opportunities and Challenges". MRS Bulletin 33, n.º 3 (marzo de 2008): 215–24. http://dx.doi.org/10.1557/mrs2008.47.
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AbstractCarbon nanotubes (CNTs) with macroscopically ordered structures (e.g., aligned or patterned mats, fibers, and sheets) and associated large surface areas have proven promising as new CNT electroactive polymer materials (CNT-EAPs) for the development of advanced chemical and biological sensors. The functionalization of CNTs with many biological species to gain specific surface characteristics and to facilitate electron transfer to and from them for chemical- and bio-sensing applications is an area of intense research activity.Mechanical actuation generated by CNT-EAPs is another exciting electroactive function provided by these versatile materials. Controlled mechanical deformation for actuation has been demonstrated in CNT mats, fibers, sheets, and individual nanotubes. This article summarizes the current status and technological challenges for the development of electrochemical sensors and electromechanical actuators based on carbon nanotube electroactive materials.
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Park, Si Won, Sang Jun Kim, Seong Hyun Park, Juyeon Lee, Hyungjun Kim y Min Ku Kim. "Recent Progress in Development and Applications of Ionic Polymer–Metal Composite". Micromachines 13, n.º 8 (11 de agosto de 2022): 1290. http://dx.doi.org/10.3390/mi13081290.
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Electroactive polymer (EAP) is a polymer that reacts to electrical stimuli, such as voltage, and can be divided into electronic and ionic EAP by an electrical energy transfer mechanism within the polymer. The mechanism of ionic EAP is the movement of the positive ions inducing voltage change in the polymer membrane. Among the ionic EAPs, an ionic polymer–metal composite (IPMC) is composed of a metal electrode on the surface of the polymer membrane. A common material for the polymer membrane of IPMC is Nafion containing hydrogen ions, and platinum, gold, and silver are commonly used for the electrode. As a result, IPMC has advantages, such as low voltage requirements, large bending displacement, and bidirectional actuation. Manufacturing of IPMC is composed of preparing the polymer membrane and plating electrode. Preparation methods for the membrane include solution casting, hot pressing, and 3D printing. Meanwhile, electrode formation methods include electroless plating, electroplating, direct assembly process, and sputtering deposition. The manufactured IPMC is widely demonstrated in applications such as grippers, micro-pumps, biomedical, biomimetics, bending sensors, flow sensors, energy harvesters, biosensors, and humidity sensors. This paper will review the overall field of IPMC by demonstrating the categorization, principle, materials, and manufacturing method of IPMC and its applications.
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Washington, Alexandrea, Ji Su y Kwang J. Kim. "Actuation Behavior of Hydraulically Amplified Self-Healing Electrostatic (HASEL) Actuator via Dimensional Analysis". Actuators 12, n.º 5 (18 de mayo de 2023): 208. http://dx.doi.org/10.3390/act12050208.
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Electroactive polymer (EAP) actuators are an example of a novel soft material device that can be used for several applications including artificial muscles and lenses. The field of EAPs can be broken down into a few fields; however, the field that will be discussed in this study is that of Soft Electrohydraulic (SEH or EH) actuators. The device that will specifically be studied is the Hydraulically Amplified Self-Healing Electrostatic (HASEL) actuator. The design of the HASEL actuator is simple. There are two compliant films that house a dielectric liquid, and with the application of a voltage potential, there is an output displacement and force. However, the actuation mechanism is more complex, thus there is a need to understand theoretically and experimentally how the actuator works. This study analytically describes the electrode closure and the experimental testing of the actuators. Then, dimensional analysis techniques are used to determine what factors are contributing to the function of the actuator. For this study, eight dimensionless Π groups were found based on the derived analytical equation. These Π groups were determined based on the input voltage, density, viscosity, and elastic modulus of the materials; these were chosen because of their major contribution to the experimental data. The Π groups that are of particular importance are related to the characteristic length, which is directly related to the displacement of the fluid, the fluid velocity, the fluid pressure, and the dielectric constant. From this study, relationships between the output force, the electrostatic contributions, and other parameters were determined. All in all, this type of analysis can provide guidance on the development of high-performance HASEL actuators.
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Huang, Cheng, Bo Bai, Baojun Chu, Jim Ding y Q. M. Zhang. "Electroactive Polymer Deformable Micromirrors (EAPDM) for Biomedical Optics". MRS Proceedings 820 (2004). http://dx.doi.org/10.1557/proc-820-o8.12.
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AbstractElectroactive polymers (EAPs) are capable of converting energy in the form of electric charge and voltage to mechanical force and movement and vice versa. Several electroactive polymer actuator materials whose responses are controlled by external electric fields, e.g. poly(vinylidene fluoride-trifluoroethylene) based fluoroterpolymers, have generated considerable interest for use in applications such as artificial muscles, sensors, parasitic energy capture, integrated bio-microelectromechanical systems (BioMEMS) and microfluidic devices due to their high electric-field induced strain, high elastic modulus, high electromechanical coupling and high frequency operation, etc. Scaling the EAP down into microsystems is one of the promising trends of EAP actuators and sensors especially for biomedical engineering. The combination of micro-optics and integrated BioMEMS, referred to as bio-micro-opto-electromechanical systems (BioMOEMS), makes a new opportunity for innovation in the EAP field. We present an approach to the fabrication of low-cost, large-stroke deformable micromirrors based on high performance electroactive polymer film microactuator arrays. Integrated Optic-BioMEMS based on electroactive polymer deformable micromirror (EAPDM) technology provide potential applications in biomedical optics such as ophthalmology (retinal imaging and vision care) and cancer detection and treatment.
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Huang, Cheng, Ji Su y Q. M. Zhang. "High-Dielectric-Constant All-Organic/Polymeric Composite Actuator Materials". MRS Proceedings 785 (2003). http://dx.doi.org/10.1557/proc-785-d3.6.
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ABSTRACTAmong various electroactive polymer (EAP) actuator materials developed recently, the class of EAPs whose responses are stimulated by external electrical fields (often known as the field type EAPs) is especially attractive due to their high strain level and elastic energy density. However, for most field type EAPs, dielectric constant is low, generally less than 10. Consequently, these polymers usually require high electric fields (>100 V/μm) to generate high elastic energy density which limits their applications. In this paper, we will investigate some avenues to significantly raise the dielectric constant and electromechanical response in field type polymeric materials. By exploiting an all-organic composite approach in which high-dielectric-constant organic particulates were blended with a polymer matrix, a polymeric-like material can reach a dielectric constant higher than 400, which results in a significant reduction of the applied field to generate high strain with high elastic energy density. An all-polymer high-dielectric-constant (K>1,000 @1 kHz) percolative composite material was fabricated by the combination of conductive polyaniline particles (K>105) within a fluoroterpolymer matrix (K>50). These high-K polymer hybrid materials also exhibit high electromechanical responses under low applied fields. In addition, a three-component all-organic composite was designed and prepared to improve the dielectric constant and the electromechanical response, as well as the stability of the composites, in which a high-dielectric-constant organic dielectric phase and an organic conductive phase were embedded into the soft dielectric elastomer matrix.
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Arnold, Allison, Ji Su y Edward Michael Sabolsky. "Nafion-Pt IPMC Electroactive Behavior Changes in Response to Environmental Nonequilibrium Conditions". Smart Materials and Structures, 14 de marzo de 2023. http://dx.doi.org/10.1088/1361-665x/acc437.
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Abstract Electroactive polymers (EAPs) continue to gain attention for their potential to offer unique and versatile solutions in the soft robotic and flexible electronic industries. Ionic Polymer-Metal Composites (IPMCs) are a class of ionic-type EAPs which can be configured as capacitor actuators with very low voltage requirements (≤ 5 V AC or DC). Their compact, portable, and lightweight properties, coupled with a biomimetic bending actuation response make them ideal for human-machine integrated technologies such as medical implants, active skins, and artificial muscles. This work tested the IPMC’s actuation and electrical response in varying saturation conditions (70 %RH, 85 %RH, 95 %RH, and DI water liquid immersion) and voltage application schemes (DCV cycled, continuously applied, and relaxation responses upon voltage removal). This information was then used to establish actuation and back-relaxation response patterns through repetitive testing for statistical certainty. These demonstrated maximized actuation in water vapor conditions where the IPMC’s dielectric is maximized (ε'≅1.37×106), and the dissipation factor is minimized (tanδ=4.6). The response trends in vapor conditions are gradual but yield larger actuation ranges with increasing hydration. Liquid immersion restricts the IPMC’s range of motion but produces a sharper response pattern. These trends were validated against previously published IPMC actuator models. All of this creates a more pragmatic perspective on the potential of this technology which aids in the advancement of this material’s evolution toward viable real-world application configurations which capitalize on the material’s natural responses.
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Hård, Daniel, Mathias Wallin y Matti Ristinmaa. "Connectivity constraints ensuring continuous electrodes in topology optimization of EAP". Journal of Mechanical Design, 4 de marzo de 2024, 1–13. http://dx.doi.org/10.1115/1.4064980.
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Abstract Electroactive polymers (EAP) deforms when subject to an electric field, which is generated by two or more electrodes. To ensure proper function of the EAP, these electrodes are connected to a source and they are therefore required to be continuous such that no isolated islands exist. Increasing an EAPs performance using topology optimization while ensuring electrode connectivity is the goal of this work. A topology optimization formulation is introduced where electrode connectivity is ensured using the Virtual Temperature Method. Numerical experiments demonstrates that this is an efficient method to guarantee connectivity.
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Li, Zhimin y Z. Y. Cheng. "Interfacial Layer - A New Mechanism for Electromechanical Response". MRS Proceedings 856 (2004). http://dx.doi.org/10.1557/proc-856-bb12.10.
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ABSTRACTElectric field induced phase transition has been used to explain the high strain response in some PVDF-based EAP. However, it is hard to understand some features (such as the relationship between the strain and the preload) of elastomers - an important type of EAPs. In this paper, we reported the study of recrystallization on high-energy-electron irradiated P(VDF-TrFE) copolymer. The morphology and structure as well as the structural transformation in the recrystallized copolymers were studied by means of X-ray diffraction, DSC, FTIR, and polarization measurements. The effect of crosslinking induced by the irradiation is discussed. The results suggest that a new interface layer existed in the recrystallized polymers. The partially ordered interfacial layer is a novel micro-origin of a high polarization obtained in an EAP. Based on this concept, the effect of preload on the E-M performance of the elastomers can be well explained. A new method to develop high performance electroactive polymer is outlined by using the interface state.
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Engel, Kyle, Paul Andrew Kilmartin y Olaf Diegel. "Additive manufacture of ionic polymer–metal composite actuators using digital light processing techniques". Rapid Prototyping Journal, 25 de octubre de 2022. http://dx.doi.org/10.1108/rpj-06-2022-0178.
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Purpose The purpose of this study is to develop a additive manufacturing (AM) process for the fabrication of ionic polymer–metal composite (IPMC) devices with complex designs that would be time-consuming to replicate using conventional manual methods. These IPMC devices have considerable potential in electroactive polymers (EAPs) and soft actuators. Design/methodology/approach This paper presents a novel three–dimensional (3D) AM technique to develop IPMCs. Digital light processing (DLP) fabrication of soft EAPs was undertaken using a vat-based AM method, followed by deposition of cost-effective outer silver electrodes. Findings DLP-fabricated devices were compared to conventional Nafion™-117 devices. DLP layer-by-layer fabrication of these devices allowed for good resolution for a range of printed objects. Electrical actuation of the DLP-produced IPMCs showed tip displacements of up to 3 mm, and greater actuation was seen in the presence of lithium rather than magnesium cations. The IMPCs showed good ion exchange capacities, while electrochemical analysis showed the reversible formation and removal of AgCl layers in addition to ion movement. Practical implications The AM of these devices allows for rapid prototyping as well as potential use in the development of multiple degrees of freedom actuators and devices. Originality/value An original resin formulation was developed for DLP 3D printing. This formula is chemically distinct from the conventional Nafion™-117 membranes that can be purchased. Additionally, this method allows for the manufacture of complex objects that would be difficult to machine by hand. These findings are of value to both the fields of polymer chemistry and AM.
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Arnold, Allison, Ji Su y Edward Michael Sabolsky. "Influence of environmental conditions and voltage application on the electromechanical performance of nafion-Pt IPMC actuators". Smart Materials and Structures, 7 de octubre de 2022. http://dx.doi.org/10.1088/1361-665x/ac986f.
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Abstract Ionic Polymer-Metal Composites (IPMCs) are a class of Ionic-type Electroactive Polymers (I-EAPs) which can be configured as capacitor actuators with very low voltage requirements (≤ 5 V AC or DC). Their compact, portable, and lightweight properties, coupled with a biomimetic bending actuation response, makes them ideal for human-machine integrated technologies such as medical implants, active skins, and artificial muscles. Unfortunately, IPMC actuator’s hydration-related sensitivity inhibits practical application in industry and makes experimental research difficult. Therefore, this research sought to quantify the hydration-related parameters of IPMC actuators by applying a wide range of experimental tests to characterize the material’s hydration-dependent features. This included saturation, dielectric, and bending actuation measurements. The IPMC’s degree of saturation properties were classified to establish sample rehydration, preparation, and preservation techniques. IPMC electrical-solvent properties were measured to estimate IPMC actuation performance based on capacitance and dissipation measurements. Maximized actuation was identified for samples tested in 95 % RH (i.e., percentage relative humidity). This condition produced a optimized displacement range and retained quality. Through statistical analysis, the work showed large electroactive performance variability (up to 50% deviation), which is a primary obstacle inhibiting this technology from practical application. Finally, an array of electrical field bias applications (i.e., cycled, constant, and post voltage removal monitoring) at intensities ranging from 0.75 to 1.2 direct current voltage (DCV) were used to quantify actuation rate, maximum displacement, as well as voltage application and removal back-relaxation behavior.
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Jacquemin, Q., Q. Sun, D. Thuau, E. Monteiro, S. Tence-Girault, S. Doizi, O. Traxer y N. Mechbal. "Design and control of a new electrostrictive polymer based continuum actuator for endoscopic robot". Journal of Intelligent Material Systems and Structures, 22 de diciembre de 2022, 1045389X2211420. http://dx.doi.org/10.1177/1045389x221142090.
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Minimally Invasive Surgery (MIS) consists of the insertion of a flexible endoscope into the patient body through natural orifices. Over the past few decades, the growing interest in microelectromechanical systems (MEMS) has paved the way for ubiquitous miniaturized integrated sensors and actuators in medical endoscopy. Nowadays, recent advances in materials have opened a promising way to fulfill the surgical requirements and size constraint for the development of smart continuum structures. Among smart materials, electroactive polymers (EAPs) exhibit exceptionally large, fast, repeatable, and reversible motions while perfectly meeting the requirements of micro-integration. However the high applied voltage required for the actuation is not compatible with in vivo medical application. To overcome these issues, a multilayered concept has been proposed. In this work a relaxor ferroelectric electrostrictive polymer is studied for its large electromechanical strain. A wide range of parameters involved in the active material has led us to the development of a finite element model on Abaqus to guide the experimental development. Then, to control this smart endoscopic robot a kinematic and a dynamic models have been built. To test and validate these models a Co-simulation procedure has been developed. This procedure coupled Abaqus and Matlab-Simulink allowing testing proposed control algorithms.
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Sharif, Montassar Aidi. "PVC gel smart sensor for robotics sensing applications: an experimental and finite element simulation study". Engineering Research Express, 28 de julio de 2022. http://dx.doi.org/10.1088/2631-8695/ac852b.
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Abstract Research is now being done on soft electroactive polymers (EAPs), such as polyvinyl chloride (PVC) gel, as an example, for use in soft robotics and smart sensors. Although the sensing behavior of PVC gel has not yet been thoroughly investigated, it has been determined that this material reacts in some way to the stimuli that come from the outside. PVC gels are being utilized to construct a broad variety of different kinds of smart sensors due to the fact that their deformation may be endlessly configured by variations in electrode arrangement, applied mechanical stress, and the amount of plasticizer contained within the gel. In this study, experimental characterizations and the results of finite element simulations are discussed for a PVC gel compression sensor. A simulation of what happens to PVC gel when it is compressed from the outside using mechanical force has been built using the COMSOL Multiphysics, which is a finite element simulation software. This simulation was used to create the simulation. In addition, experimental measurements of PVC gels are carried out in order to validate the underlying principles that have been presented thus far by providing context for the results of the simulations and to validate the findings of the simulations effectively. Based on the findings, it appears that the suggested sensor is able to detect compression at a variety of amplitudes and speeds.
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Sharma, Atul Kumar. "Design of a Command-Shaping Scheme for Mitigating Residual Vibrations in Dielectric Elastomer Actuators". Journal of Applied Mechanics 87, n.º 2 (5 de diciembre de 2019). http://dx.doi.org/10.1115/1.4045502.
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Abstract Dielectric elastomers (DEs) are a class of highly deformable electroactive polymers (EAPs) employed for electromechanical transduction technology. When electrostatically actuated dielectric elastomer actuators (DEAs) are subjected to an input signal comprising multiple Heaviside voltage steps, the emerging inherent residual vibrations may limit their motion accuracy in practical applications. In this paper, the systematic development of a command-shaping scheme is proposed for controlling residual vibrations in an electrically driven planar DEA. The proposed scheme relies on invoking the force balance at the point of maximum lateral stretch in an oscillation cycle to bring the actuator to a stagnation state followed by the application of an additional electric input signal of predetermined magnitude at a specific time. The underlying concept of the proposed control scheme is articulated for a single Heaviside step input-driven actuator and further extended to the actuator subjected to the multistep input signal. The equation governing the dynamic motion of the actuator is derived using the principle of virtual work. The devised dynamic model of the actuator incorporates the effects of strain stiffening of elastomer and viscous energy dissipation. The nonlinear dynamic governing equation is solved using matlab ode solver for extracting the dynamic response of the actuator. The applicability of the devised command-shaping control scheme is illustrated by taking a wide range of parameters including variations in the extent of equilibrium state sequences, damping, and polymer chain extensibility. The proposed scheme is found to be adaptable in controlling the vibrations of the actuator for any desired equilibrium state. The results presented in this paper can find its potential application in the design of an open-loop control system for DEAs.
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Rasmussen, Lenore, Simone Rodriguez, Matthew Bowers, Damaris Smith, Greig Martino, Livia Rizzo, Cole Scheiber, Jesse D’Almeida y Curran Dillis. "Adjustable Liners and Sockets for Prosthetic Devices". Canadian Prosthetics & Orthotics Journal, 15 de diciembre de 2018. http://dx.doi.org/10.33137/cpoj.v1i2.32048.
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INTRODUCTION
Ras Labs’ Synthetic Muscle™ will allow amputees to continue their active lives without needing to adjust the fitting of their prosthetic device(s) throughout the day. This technology promises to resolve major issues facing amputees, most notably the pain of prosthetic slippage and tissue breakdown. Synthetic Muscle™, comprising electroactive polymers (EAPs), actively expand or contract at low voltages, while offering impact resistance and pressure sensing, all in one integrated solution. The main objectives of this project is to determine the feasibility of the EAP pads incorporated into prosthetic liners or sockets and to create prototypes of these EAP based shape-morphing pad systems. In collaboration with UPI, testing of these EAP based pads located in strategic areas of the socket was initiated with customers (BK and AK) for evaluation and feedback. Characterization of Synthetic Muscle™ as dual use pressure sensors was initiated. This is a continuation Ras Labs’ dynamic prosthetic pad project, which demonstrated how the volume of the EAP can be changed from applying a low voltage and operating temperatures for use in adjustable prosthetic liners and sockets 1-8.
Abstract PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/32048/24462
How to cite: Rasmussen L, Rodriguez S, Bowers M, Smith D, Martino G, Rizzo L, Scheiber C, d’Almeida J, Dillis C. Adjustable Liners and Sockets for Prosthetic Devices. CANADIAN PROSTHETICS & ORTHOTICS JOURNAL, VOLUME 1, ISSUE 2, 2018; ABSTRACT, POSTER PRESENTATION AT THE AOPA’S 101ST NATIONAL ASSEMBLY, SEPT. 26-29, VANCOUVER, CANADA, 2018. DOI: https://doi.org/10.33137/cpoj.v1i2.32048
Abstracts were Peer-reviewed by the American Orthotic Prosthetic Association (AOPA) 101st National Assembly Scientific Committee.
http://www.aopanet.org/
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Doregiraei, Mohammad Javad, Hossein Moeinkhah y Jafar Sadeghi. "A fractional order model for electrochemical impedance of IPMC actuators based on constant phase element". Journal of Intelligent Material Systems and Structures, 26 de noviembre de 2020, 1045389X2097443. http://dx.doi.org/10.1177/1045389x20974438.
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The accurate modeling of electrical impedance over a wide range of frequency is essential for precise dynamic modeling and control problems of Electroactive Polymer (EAP) actuators. Recently, fractional order modeling has attracted more attention due to the high accuracy. This paper deals with a fractional order electrical impedance model and its identification procedure for a class of EAP actuator named Ionic Polymer Metal Composite (IPMC). To take IPMC’s fractional characteristic into account, constant phase element (CPE) is used to construct a model structure according to Electrochemical Impedance Spectroscopy (EIS). By employing the Levy’s method in combination with genetic optimization algorithm, the unknown parameters of the resulting fractional transfer function are identified. Finally the proposed model is verified, by comparing with experimental EIS data. The results show that the fractional order model has high accuracy for representing the electrical impedance of IPMC actuator. The proposed modeling procedure is general and can also be used for any type of EAPs.
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Zeng, Haibing, Silian Fu, Yongri Liang y Li Liu. "Effect of Branched Structure on Microphase Separation and Electric Field Induced Bending Actuation Behaviors of Poly(urethane–urea) Elastomers". Smart Materials and Structures, 5 de diciembre de 2022. http://dx.doi.org/10.1088/1361-665x/aca8dd.
Texto completoResumen
Abstract Polyurethane elastomers (PUEs) as a type of electroactive polymers have wide applications in soft actuators, soft sensors and energy harvesting due to their high dielectric constant, high electrostriction coefficients, easy processing and structure adjustability, and superior biocompatibility etc. However, the relationship between microstructure and electromechanical properties of EAEs has not been fully understood. In this work, we fabricated the branch structured poly(urethane-urea) elastomers (PUUs) using hydroxy-terminated polybutadiene (HTPB) as soft segment, isophorone diisocyanate (IPDI) and 4,4-diaminodicyclohexylmethane (PACM) as hard segment, and hydroxyl-terminated four-armed polycaprolactone (PCL410) as branch structured chain extender for improving bending actuation performances, and understanding the relationship between structure and electromechanical properties. The degree of branched structure of PUUs were adjusted by the content of PCL410. The microphase separation kinetics of PUUs was enhanced as increase of PCL410 content, whereas the degree of microphase separation and hard domain (HD) size of PUUs were reduced. The mechanical loss and bending actuation stress of PUUs were significantly improved by incorporation of small amount of branched structure into PUU chains. The PUU with 2.60 mol.% of PCL410 showed 5.16 mm of bending displacement and 5.16 Pa of bending actuation stress at 7.2 kV (corresponding to 180 V/mm of the nominal electric field), which were 76.3, and 79 times higher than that of PUU without PCL410, respectively. The electric field induced bending actuation mechanism of branch structured PUUs was suggested that the bending actuation mechanism of branch structured PUUs is caused by electrostrictive effect from dipole orientation induced bending deformation of constrained segments and asymmetric charge density distribution on both anode and cathode sides of PUU films. Our results can provide new insight on design novel electroactive polyurethane elastomers.