View the article online for updates and enhancements.

Dielectric elastomer transducers (DET) belong to the group of electroactive polymers and consist of an elastic dielectric layer laminated between two compliant electrodes. In order to reduce the driving voltage and at the same time maintain appreciable deformation, multilayer systems are common nowadays. Due to their complex manufacturing process, available transducers typically exhibit small aspect ratios in the range of 1:10–2:1 (length/diameter or height/width). Since DET have similar properties to a human muscle, it appears logical to use them in human machine interaction. Therefore, special transducer designs and an adapted dip coating fabrication method for aspect ratios higher than 16:1, which are required for soft robotic applications, are presented within this work. The polydimethylsiloxane (PDMS) raw material Elastosil 2030 (Wacker Chemie AG) and particle-based electrode blends are used to build elongated multilayer tubular transducers with up to 10 layers and 100 mm in length. Moreover, different designs and integrated stiffening elements are simulated with Ansys multiphysics FEM tool. As shown in measurements, the absolute deformation can be increased by more than 40%.

Dielectric elastomer transducers (DETs) consist of an elastic dielectric film sandwiched between compliant electrodes. Applying an electric voltage leads to an electrostatic pressure between the electrodes which causes a deformation of the DET due to the elastic dielectric. The dielectric breakdown field strength of the elastomer restricts the applied voltage. For highly efficient DETs, their dielectric breakdown strength during operation has to be known. In this work, eight different breakdown test scenarios with self-fabricated single-layer DET samples made of the silicone film Elastosil® Film 2030 (Wacker Chemie AG) are conducted. They differ in type of the applied electrical voltage (DC/AC), mechanical load of the silicone film and setup of the DET samples. The DETs show a nominal dielectric breakdown strength between 96 and 200 V μm−1 during operation depending on the applied voltage, prestretch and the setup of the DET. Applying protective silicone film layers on top and bottom of the electrodes leads to a reduced damage of the DET after the breakdown of the weakest point and prevents the complete failure of the transducer.