Nonlinear Lumped Parameter Model and Snap-Through Stability Analysis of Hydraulically Amplified Dielectric Elastomer Actuators

Hydraulically amplified dielectric elastomer actuators (HADEAs) are soft actuators comprising a pair of elastic electrodes connected to an inflatable membrane where the membrane and space between the electrodes are filled with an incompressible dielectric fluid. A lumped parameter model (LPM) was developed based on a nonlinear hyper-elastic Mooney-Rivlin material model. We compared the nonlinear LPM with a previous linear model and with a multiphysics finite element model with Mooney-Rivlin materials. The proposed nonlinear LPM showed good agreement in the estimation of strain and internal hydrostatic pressure as a function of actuation voltage compared to the finite element analysis results. Moreover, it better predicts the quasi-static equilibrium state and snap-through instability than the linear LPM.