A Modulated Voltage Waveform for Enhancing the Travel Range of Dielectric Elastomer Actuators

Abstract

This paper presents a method to achieve high deformability levels in dielectric elastomer actuators (DEAs) by applying a modulated voltage waveform. The method relies on supplying the electrostatic energy during the specific phase of the oscillation cycle, resulting in the enhanced travel range at a relatively low driving voltage. We consider a standard sandwich configuration of the DE actuator with neo-Hookean material model and outline an energy-based approach for delineating the underlying principles of the proposed method. A comparison of the deformability levels achieved using the quasi-static, Heaviside step, and the modulated input waveforms is presented. Significant reduction in instability voltages together with a considerable increase in the stable actuation limit is observed in the case of the modulated voltage input. The estimates of the stability thresholds are validated by integrating the equation of motion obtained using Hamilton's principle. The effect of energy dissipation is assessed by considering variations in the quality factor. Further, a qualitative comparison with experimental observations is presented highlighting the practical feasibility of the method. This investigation can find its potential use in the design and development of DEAs subjected to a time-dependent motion.

Dynamical behavior of a particle-doped multi-segment dielectric elastomer minimal energy structure

“…It is worth mentioning that various models have been applied to describe hyperelastic materials, such as the Neo-Hookean [3,37,38,48], Ogden [14,36], Mooney-Rivlin [1,15,25,44], Yeoh [43], Gent [35], and Arruda-Boyce [28] models. The Gent model is adopted in the present study considering the ultimate stretching of the particle-doped DE membrane.…”

“…The reversible large deformation characteristics [3,4,30] and other significant properties of DEs have led to their extensive application in various configurations, such as the DE minimum energy structure (DEMES). DEMES is a selfassembling structure driven by electric fields, capable of achieving complex deformations and functionalities.…”

Effect of anisotropy on the dynamic electromechanical instability of a dielectric elastomer actuator

“…For describing the effect of anisotropy on the electromechanical actuation behaviour of DEs, we present the material model of anisotropic incompressible dielectric elastomers following the same approach used for isotropic dielectrics [43]. In order to model the elastic behaviour of isotropic dielectric elastomers, different hyperelastic material models such as neo-Hookean [10,20,44,45], Mooney-Rivlin [40,46], Ogden [40,44,46], Gent [47,48], Yeoh [9,49], and Arruda-Boyce [50] have been used so far in the literature. In the present investigation, we assume that the dielectric elastomer membrane is made of generalized neo-Hookean material, which is transversely isotropic about one of the lateral direction, i.e., X 1 .…”

“…For improving the electromechanical actuation performance of DEAs, several promising methods have been adopted to circumvent the electromechanical instability [20][21][22][23][24]. The most widely used technique for improving the actuation is pre-stretching or prestressing the elastomer before applying the electric load [22].…”