Multilayer dielectric elastomer tubular transducers for soft robotic applications

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 to 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%