Humidity Effect on Dynamic Electromechanical Properties of Polyacrylic Dielectric Elastomer: An Experimental Study

Abstract

In this research, by utilizing the Very-High-Bond (VHB) 4905 elastomer, we carry out an experimental examination on the humidity effect on dynamic electromechanical performances of dielectric elastomers, including the dynamic response and viscoelastic creeping. Firstly, we experimentally analyze effects of the pre-stretch, peak voltage, waveform and frequency of the dynamic response of VHB 4905 elastomer under several ambient humidities. In general, the amplitude of dynamic deformation gradually adds up with the increasing humidity. Besides, it is found that the amplitude affected by different parameters shows diverse sensitivity to humidity. Subsequently, effect of humidity on the viscoelastic creeping of VHB 4905 is explored. The results demonstrate that, subject to different ambient humidities, the viscoelastic creeping under Alternating Current (AC) voltage is similar to that under Direct Current (DC) voltage. Furthermore, the equilibrium position of dynamic viscoelastic creep enlarges gradually with the humidity, regardless of voltage waveforms. For the dielectric elastomer with a pre-stretch ratio of 3, when the humidity increases from 20% to 80%, the increase of average equilibrium position of dynamic viscoelastic creep is larger than 1599%.

Modelling and simulation of a commercially available dielectric elastomer actuator

“…Based on the results, this simplification seems appropriate. Furthermore, silicone, as a membrane material, has high stability against temperature and humidity [67,68].…”

Dielectric Elastomer-Based Actuators: A Modeling and Control Review for Non-Experts

“…Early claims [35,168] suggested that creep would not significantly affect most applications, though more recent studies suggest that viscoelastic behavior can degrade motion performance [170] and cause energy loss [171]. In terms of environmental tolerance, manufacturer [172][173][174], increases current leakage [58], and decreases the dielectric breakdown strength of VHB 4910 [175] so that it can be exploited in humidity sensor applications [58]. Similar effects on dielectric breakdown strength were reported for silicone elastomers, though not to the same extent as acrylic [175].…”