Active tensegrity structures based on dielectric elastomer actuators

Robotic systems based on tensegrity structures have been widely studied in recent years due to their unique characteristics such as lightweight property, deformability, and modularity. These features are originated from the structural configuration of tensegrity that consists of rigid rods connected and stabilized by pre-stretched elastic cables. However, most of the tensegrity robotic systems are driven by electromagnetic motors, which can make their structure bulky and complicated. In this contribution, we present tensegrity structures using dielectric elastomer actuators (DEAs). In these active tensegrity structures, DEAs are used as the elastic cables, allowing them to generate voltage-controlled deformations. Thanks to the multifunctional nature of DEAs, this configuration also enables the sensing of deformations. Given the large actuation strokes and high compliance of DEAs, the DE-tensegrity is expected to become a multifunctional building element for soft robotic systems. In order to prove the concept, we fabricate a DE-tensegrity using an acrylic elastomer (3M, VHB4905) and acrylic (poly(methyl methacrylate)(PMMA)) plate that are used for DEAs and the rigid rods, respectively. A conductive acrylic elastomer is used as the electrodes of DEAs. We characterize the active tensegrity to clarify the actuation and sensing performance and discuss the results.