Nonlinear Dynamics of a Magnetically Coupled Dielectric Elastomer Actuator

The magnetically coupled dielectric elastomer actuator (MCDEA) is an emerging two-degree-of freedom DEA system that demonstrates rich dynamic behaviours and promising potential applications in robotics, energy harvesting and smart structures. However, the three-dimensional geometry, nonlinearity and viscoelasticity in the system leads to complex nonlinear dynamic behaviour which is challenging to predict. In this work, we develop a numerical model that can accurately characterize its dynamic responses. This model, along with experimental results, demonstrate the complex dynamic phenomena of this MCDEA system, including super-harmonic, primary harmonic and subharmonic resonances, bifurcations and multiple modes of oscillation. Novel dynamic control strategies including phase tuning and frequency control are proposed in this work, allowing for control of the amplitude and the appearance of a specific resonance and the occurrence of emerging dynamic behaviours such as beat phenomena. These findings have numerous additional areas including active vibrational control, energy harvesting and programmable soft motors for on-demand locomotion.