Among ElectroActive Polymers(EAPs) the dielectric elastomer actuator is regarded as one of the most practically applicable in the near future. So far, its effect on the actuation phenomena has not been discussed sufficiently, although its strong dependency on prestrain is a significant drawback as an actuator. Recent observations clarifies that prestrain has the following pros and cons: prestrain plays an important role in generating large strain, whereas it rather contributes to the reduction of the strain. Prestrain provides the advantages of improving the response speed, increase of the breakdown voltage, and removing the boundary constraint caused by the inactive actuation area of the actuator. On the contrary, the elastic forces by prestrain makes the deformation smaller and the induced stress relaxation is severely detrimental as an actuator. Also, the permittivity decreases as prestrain goes up, which adds an adverse effect because the strain is proportional to the permittivity. In the present work, a comprehensive study on the effects of prestrain is performed. The key parameters affecting the overall performances are extracted and it is experimentally validated how they work on the actuation performance.
In this paper we present a dielectric elastomer actuator, which has the ability to sense the force acting on it without any additional sensing device. Basic physical behaviors of the dielectric elastomer are experimentally investigated and it is noted that the impedance of the dielectric elastomer varies depending on external forces acting on it. Based on that concept, we propose the principle of a self-sensing actuator according to experimental result. In addition, a multi-stacked actuator with self-sensing capability is realized to validate its feasibility.
As a major human sensory function, the implementation of the tactile sensation for the human-machine interface has been one of the core research interests for long time. In this research, tactile display devices based on dielectric elastomer are introduced among the works recently done by ourselves. Using dielectric elastomer for the construction of the tactile interface, it can provide stimulation on the human skin without any additional electromechanical transmission. Softness and flexibility of the device structure, ease of fabrication, possibility for miniaturization, and cost effectiveness are the representative benefits of the presented devices. Especially, the device application is open to a wide variety of purposes since the flexible structure offers excellent adaptability to any contour of the human body as well as the other objects. In this paper, the design of the interfaces is briefly explained and several examples of implementation are introduced.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.