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Polymers in Special Uses
Published in Manas Chanda, Plastics Technology Handbook, 2017
Electroactive polymers (EAPs) are polymers that exhibit a change in size or shape when stimulated by an electric field. The most common applications of this type of material are in actuators and sensors. In EAP actuator technology, a lightweight polymer responds to an electric field by generating mechanical motion. Because of their ability to mimic the properties of natural muscle, EAPs have also been termed electroactive polymer artificial muscle (EPAM). A number of materials have been explored for their use as artificial muscles. Among these, dielectric elastomers (DEs) appear to provide the best combination of properties for true muscle-like actuation. DEs behave as compliant capacitors, expanding in area and shrinking in thickness when a voltage is applied. A simple example of DE is natural rubber. A film of natural rubber can be made to change in shape by applying a large electric field across it.
Electroactive Polymers for Packaging Technology
Published in Inamuddin, Mohd Imran Ahamed, Rajender Boddula, Adil A. Gobouri, Electroactive Polymeric Materials, 2022
Pinku Chandra Nath, Ria Majumdar, Tarun Kanti Bandyopadhyay, Biswanath Bhunia, Biplab Roy
In this era of emerging technologies, conventional materials (e.g., metals, alloys, and ceramics) have been replaced by polymers, such as homopolymers, copolymers, blends of small molecules, complexes, and composites, which are being used in household goods, aerospace, automobiles, packaging industries, electronics, and medical sciences. These polymeric materials have tremendous advances; therefore, several processing techniques have been developed to date, and are being developed to enable polymer production with tailor-made properties (e.g., physical and mechanical). Theses feature of polymers that allow the invention of new designs with cost-effective and light weights makes them interesting for growing technologies (Guru Nathan et al., 1999). However, unlike inorganic materials, polymers have different attractive properties, for example, they are light weight, easily processed, pliable, and fracture tolerant. These can be configured into various complex shapes and their properties can be tailored into what is required (Bar-Cohen, 2004). Different materials with artificial intelligence and rapid advances (e.g., piezoelectric materials and shape memory materials) can sense changes in the environment, process that information and then respond accordingly (Irinyi, 2000). Polymers that respond to external stimuli, for example, pH, electrical field, light, and magnetic fields by changing their shape or size are active polymers and have been known for several decades (Bar-Cohen, 2004). Therefore, polymers that change shape, or dimensions, or both when exposed to an electric field are electroactive polymers (EAPs) (Carpi and Smela, 2009).
IoT End Devices
Published in Rebecca Lee Hammons, Ronald J. Kovac, Fundamentals of Internet of Things for Non-Engineers, 2019
Electroactive polymers—Using electricity as the energy source, and a switch or computer signal as the control signal, creates linear motion. Electroactive polymers exhibit a change in size or shape when stimulated by an electric field. One common application of these is in robotics in the development of artificial muscles (Figure 5.14).
Product ergonomics in industrial exoskeletons: potential enhancements for workforce efficiency and safety
Published in Theoretical Issues in Ergonomics Science, 2020
Pranav Madhav Kuber, Ehsan Rashedi
Various smart materials along with their properties along with their advantages and disadvantages are listed in Table 1. Among the tunable materials, electroactive polymers (EAP) are known to provide a variation in size in presence of electrical stimulation (Manti, Cacucciolo, and Cianchetti 2016). EAP can be classified based upon the actuation method: Ionic EAP – which causes shape change by the mobility of ions, and electronic EAP – which use electric fields. Types of ionic EAPs are gels, metal-polymer composites, conductive polymers and carbon nanotubes, while electronic EAPs include electrostrictive, electrostatic, piezoelectric and ferroelectric polymers (Bar-Cohen 2005). Ionic EAPs exhibit substantial circular deformation, and a study found that using polymer patterns resulted in sharp bending angles that were more than 90 degrees (Hong et al. 2017). EAP offers higher response speed, lower density, and greater resilience, all of which can benefit from building an adaptive exoskeleton structure (Bar-Cohen 2005). With further research, beams of large sizes can be developed to provide an effective adaptive and assistive mechanism to the human body. However, challenges posed in terms of selecting the right type of polymer, coalescing with other materials to obtain the required force and the feasibility of electrical stimulation on a wearable device, instigate a need for further exploration.
Technologies used in responsive facade systems: a comparative study
Published in Intelligent Buildings International, 2022
Negar Heidari Matin, Ali Eydgahi
Electroactive polymers (EAPs) are a group of ultra-lightweight, fixable, and smart materials that change their size and shape based on environmental conditions (Stoughton 2017). These materials are composed of a polymeric membrane that is sandwiched between two electrodes. Applying a high voltage to these materials causes deformation in the polymer because of electrostatic forces that exist between the two electrodes (Mondia 2014). As illustrated in Figure 9, the Decker Yeadon LLC has utilized the adaptation features of EAPs to design a prototype to control daylight penetration of a Homeostatic facade system in 2011. This system contains a flexible core covered with EAP-actuators that are capable of bending based on expansion and contraction of the material (Minner 2011).