Method towards optimal design of dielectric elastomer actuated soft machines

Soft machines are combinations of hard and soft active materials, thus the coupling and interaction between soft and hard components dictate the performance of soft machines. Structural optimization has been intensively used for design of conventional hard machines, while, to our best knowledge, few attempts have been made towards optimal design of soft machines. Here, we describe the sizing optimization problem of a dielectric elastomer (DE) actuated mechanical amplifier, and achieve the optimal design through combination of a commercial finite element method (FEM) software and an optimization automation software. We then design, fabricate and demonstrate a locomotive soft machine driven by DE actuator with amplified displacement output. The methodology and results present here open the door towards optimal designs of active materials based soft machines.