A comparison between silicone and acrylic elastomers as dielectric materials in electroactive polymer actuators

Abstract

Soft elastomers, mostly silicones and acrylics, are interesting candidates as dielectric materials in electroactive polymer actuator technology. Generally, characteristics like large strain, high stress, high energy density, good efficiency and high response speed are required for actuator applications. However, some of these material properties may be contradictory. For this reason a comparison between Dow Corning silicone and 3M acrylic elastomers was made based on a set of six electromechanical tests for actuator applications. The silicone elastomer shows a fast electromechanical response (3 s) with good reproducibility and the dissipated work is negligible and not frequency dependent. It also shows a stable mechanical behaviour over a wide temperature range. In contrast, the acrylic elastomer shows a slow electromechanical response with poor reproducibility. The dissipated work of the acrylic elastomer is significant: a strong frequency and temperature dependency of the dissipated work is observed for this material. The Dow Corning silicone (DC 3481) is a better material for many applications, where activation strains of less than 10% are sufficient. However, in applications where higher strains are required, it might be obligatory to use acrylic elastomers, because only these have the potential for use with activation strains beyond 10%. The electrical activation of a circular specimen is most useful in order to evaluate a material as a dielectric in electroactive polymer actuators.

Effect of mechanical parameters on dielectric elastomer minimum energy structures

“…In addition, silicone elastomers such as PDMS (Polydimethylsiloxane) exhibit fast response speed and wide thermal tolerance compared to acrylic elastomers (i.e. 3M VHB) [7][8][9]. As well as actuation, DEA can act as sensor [10], generator [11] and switch [12], which are promising to construct intelligent integrated soft systems.…”

Fabrication of transmissive dielectric elastomer actuator driven tunable optical gratings with improved tunability

“…25 Fast and accurate tuning of optical parameters, such as focal length and grating period, are essential for tunable optical devices. Also important is the ability to hold to a stable state for an extended time.…”

Dynamic Electromechanical Response of a Viscoelastic Dielectric Elastomer under Cycle Electric Loads

“…What is more, the viscoelastic relaxation time of VHB ranges from hundreds of microseconds to hundreds of seconds [39,40] and affects the creeping deformation of DE; that is, the enhancement of the prestretch (prestretch provides advantages to the electromechanical actuation to improve the electrical breakdown strength, avoiding instability and reducing the geometric thickness) followed by short relaxation approximately doubles that of the same prestretch but with long relaxation [9,34]. However, the relaxation time effects are seldom analyzed in the scope of viscoelasticity.…”