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

Yuchen Zuo,Lei Liu,Junshi Zhang,Jianwen Zhao,Mingliang Zhu,Yuxi Ding

doi:10.3390/polym13050784

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%.

Highlights

It is demonstrated that the dynamic displacement of VHB 4905 gradually increases with the increasing humidity under the actuation of a random voltage waveform
We investigate the humidity effect on the dynamic electromechanical properties of VHB 4905 elastomer
The amplitude of dynamic deformation gradually increases with the increasing humidity

Summary

Introduction

Dielectric elastomers (DEs), a category of soft electro-active polymers, have gained much attention recently because of their excellent properties, such as high energy density, large deformability fast response and so on [1,2,3,4,5,6]. The majority of DE materials belong to macromolecular polymers, which are very sensitive to the external environment, such as the temperature and humidity. The electromechanical deformation and stability of DEs is greatly affected, when exposed to the external environment. The researchers have found that the temperature effect plays an important role in determining the static electromechanical actuation of DEs [14,15,16,17,18,19,20]

Methods

Results

Conclusion