Dielectric elastomer artificial muscles (Energy harvesting and high-efficiency actuation)

Short Communication
2017 J Mater Eng Appl   unpublished
Chiba S Chiba S. Dielectric elastomer artificial muscles (Energy harvesting and high-efficiency actuation). J Mater Eng Appl October-2017;1(1):2-4. Growth in world population and further industrialization combined with concerns about global climate change is causing a surge in demand for clean and renewable energy. This paper discusses the potential of DE (dielectric elastomer), a new energy transduction technology that can be used to harvest energy from the environment or human activities as
more » ... man activities as well as save energy by making light and efficient motors and other devices. In the near future, most of the actuators will be replaced by DE and it will be adopted for many generators. DE SUMMARY AND OPERATING PRINCIPLE DEs are a new type of transducer technology that were first investigated by SRI International (Perline et al.) in 1991 [1]. DE has a very simple structure comprised of a polymer film (elastomer) sandwiched between two electrodes made of a flexible and elastic material [2]. Applying a voltage difference between the two electrodes causes a compression in the horizontal direction and a stretching along the surface [2] (see Figure 1). Figure 1: Principle of DE actuator. Using DE elements, a variety of devices can easily be made, such as linear actuators, diaphragm actuators for fluid pumps, and actuator arrays [3]. Its low cost, light weight, softness, high efficiency, and quietness make the actuator suitable for robots, motors, speakers, and smart materials. The DE actuator has a fast speed of response (over 100,000 Hz has been demonstrated for small strains), with a high strain rate (up to 600%) [4]. The DE having only 0.1 g of DE materials can lift a weight of 2 kg, using carbon system electrodes [4]. This is suitable for the hands or feet of robots. Furthermore, the DE can be applied to new functional devices far beyond the actuators, such as new types of DE compliant sensors and electrical power generators [4]. DEVELOPMENT OF DE ACTUATORS As elastomers are light and deform like rubbers, they can show flexible movements like bionic actions. They can express "flexible and natural feeling" which systems with motors cannot imitate. In addition to above, DE actuators do not use any gears and cams, thus enabling high efficiency and safe and smooth driving even if the speed or direction of movement are suddenly changed. Application of Robots (include Care and Rehabilitation Purpose) A wide array of proof-of-principle devices for use in legs and arms of robots (see Photo 1), swimming robots, snake like robots, compact inspection robots, gecko like robots for climbing up perpendicular walls or across ceilings, and flying robots, as well as in achieving compatibility with living organisms are currently developed [5]. The leg robot is particularly unique. It has role actuators having 3-DOF, as shown in Figure 2 [5], so it enables sideways stepping like a crab without turning around, when it collides with wall.