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

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.