Viscoelastic effect and creep elimination of dielectric elastomers in adversarial resonance

Dielectric elastomers are known to exhibit viscoelastic properties. When they are used in an adversarial resonator structure (known as a DEAR), the performance obtained is time-dependent. A thermodynamic model, involving the rheological model, is established to investigate the effect of viscoelasticity on the dynamic response. We verified the validity of our model by comparing with the experimental results. Based on the model, we theoretically analyze how the viscoelasticity is affected by the peak voltage, frequency, pre-stretching, temperature, and the shape of the signal waveform. The equilibrium position of the deformed membrane is found to drift severely during vibration, which can be attributed to the high viscoelasticity of the membrane. This behavior can lead to issues when designing precise instruments, and the drift of the equilibrium position can also result in the expansion of the amplitude envelope. We further demonstrate that under certain alternating electric loads, the viscoelastic drift of the equilibrium position is identical to the slow viscoelastic creep observed when the corresponding effective DC voltage is applied. Based on these findings and the adversarial mechanism of the DEAR structure, two strategies based on DC and AC offset correction are proposed to eliminate the viscoelastic drift. Simulation results show that applying AC offset correction has the additional benefit of allowing the amplitude of vibration to be continuously tunable over a specific range. Published by AIP Publishing.