Dielectric elastomer transducers exhibit extraordinary actuator properties due to their huge actuation, small construction volume and low energy consumption. Dielectric elastomer actuators (DEA) consist of a thin dielectric elastomer (DE) film covered with stretchable electrodes on both surfaces. If a high voltage is applied, the electrodes attract each other which leads to a reduction of the elastomer film thickness and due to the incompressibility of the elastomer film to an actuator area enlargement. Based on extensive developments, a variety of actuator forms are standard in research and, in some cases, in application. With special designs, such as out-of-plane actuators, dielectric elastomer actuators are able to transmit larger forces with deflections in the range of around one millimeter. Here, we present the fabrication and characterization of DE multilayer actuators as well as their embedding in out-of-plane actuators. In detail, the multilayer actuator consists of eight elastomer layers with thicknesses of 100 μm each and electrode widths of 30 mm and lengths of 50 mm or 80 mm. The developed multilayer actuators provide in-plane deflections of about 2% and out-of-plane deflections of about 400 μm and 800 μm for actuators with lengths of 50 mm and 80 mm, respectively, when operated with an electric field of 50 MV/m. The out-of-plane multilayer actuators exhibiting a blocking force of e.g. 1.8 N at an electric field of 70 MV/m. In order to describe the actuator behavior, an analytical model based on the neo-Hookean hyperelastic material model is developed. The comparison of the calculated and experimental data shows a good agreement for the in-plane investigations of the actuator multilayers and an approximate agreement for the out-of-plane actuators.
Dielectric elastomer (DE) transducers consist of a dielectric elastomer layer coated with flexible electrodes on both surfaces. Apart from the dielectric film, the properties of the electrodes affect the electromechanical behavior of the DEtransducers as well. Electrodes must be able to sustain conductivity at large deformations, must exhibit a low stiffness and provide sufficient adhesion to the DE-layer. Different processing technologies exist for application of electrodes suitable for DE-transducer. Among them, the inkjet printing technique gained attention in recent years as a very precise and purely non-contact deposition method to fabricate thin electrode layers. In contrast to other methods, e. g. using a shadow mask in case of spraying, the inkjet technique is very versatile and allows a fast adjustment of the processed electrode geometry. In order to describe the requirements of the inkjet printing process and ink adaptation itself, we present a theoretical description of those processes accompanied with the definition of parameters, which need to be considered during experimental processing. Furthermore, we present first results of our adaptation of an ink formulation and an inkjet printing procedure. For this purpose a commercial electrode paste, Elastosil LR 3162, made of carbon black-silicone composite, was adapted to the inkjet printing process. In first experimental studies, the adapted ink was inkjet printed onto dielectric elastomer layers by varying the inkjet printing parameters. Different measurements were performed in order to characterize separate dots as well as continuous lines and areas of the inkjet printed electrodes. The electrode thicknesses and its shapes were recorded by surface-profile measurements. The electrical properties of the printed electrodes as well as their mechanical influence on the elastic properties of the elastomer layers were measured under continuous and cyclic mechanical stretching.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.