For dielectric elastomers (DEs), the inherent viscoelasticity leads to a time-dependent deformation during actuation. To describe such a viscoelastic behavior, a constitutive model is developed by utilizing a combined Kelvin-Voigt-Maxwell (KVM) model. The established model captures both the initial jumping deformation and the following slow creeping. Subsequently, with an employment of VHB 4910 elastomer, experiments are performed to validate the viscoelastic KVM model. The results indicate a good agreement between the simulation and experimental data. Effect of the parameters in KVM model on the viscoelastic deformation of DEs is also investigated.

Prenatal alcohol exposure is associated with long-term changes in dendritic spines and synaptic ultrastructure; these alterations probably reflect the developmental retardation of dendritic spines and synapses in visual cortex. These long-term changes are likely to contribute to lifelong mental retardation associated with childhood FASDs.

Subject to a mechanical load or a voltage, a membrane of a dielectric elastomer deforms. As for the deformation mode, the dynamic performance and stability are strongly affected by how mechanical forces are applied. In the current study, by using the Euler-Lagrange equation, an analytical model is developed to characterize the dynamic performance of a homogeneously deformed viscoelastic dielectric elastomer under the conditions of equal-biaxial force, uniaxial force, and pure shear state, respectively. Numerical results are shown to describe the electromechanical deformation and stability. It is observed that the resonant frequency (where the amplitude-frequency curve peaks) has dependencies on the deformation mode, the level of mechanical load, and the applied electric field. When a dielectric elastomer membrane is subject to equal-biaxial force or pure shear state, it undergoes a nonlinear quasi-periodic vibration. An aperiodic motion of the dielectric elastomer system is induced by the boundary condition of a uniaxial force. V