Field Driven Stiffness Control of Legged Robotic Structures Using Dielectric Elastomers

Dielectric elastomers are known for their electro-mechanically coupled constitutive behavior which has demonstrated the potential for developing a number of novel adaptive structures. Despite the advances in understanding these materials using nonlinear field theory and experimental characterization, several questions remain regarding how to effectively integrate these materials in adaptive robotic structures. Here, a new design is proposed to integrate these materials into legged robotic structures that can achieve relatively large and rapid stiffness changes for enhanced mobility and agility of a field demonstrated hexapod robot. A set of resonance test are performed to quantify changes in effective stiffness as a function of the applied electric field. The results are incorporated into a bi-layer beam model to estimate changes in the effective stiffness of a robotic C-shaped leg. The results show promise for developing adaptive robotics legs for multi-terrain mobility.