Deformation mechanisms of electrostrictive graft elastomer

Abstract

The electrostrictive graft elastomer is a new type of electroactive polymer. Recently developed by NASA, it consists of flexible backbone chains, each with side chains, called grafts. Neighboring backbone grafts physically cross-link and form crystal units. The flexible backbone chain and the crystal graft unit consist of polarized monomers, which contain atoms with electric partial charges, generating dipole moments. When the elastomer is placed into an electric field, external rotating moments are applied to the dipole moment. This stimulates electrostrictive strain in the graft elastomer. In this paper, the deformation of the elastomer under the action of an electric field is explained by means of two dominant mechanisms: crystal graft unit rotation and backbone chain reorientation. A two-dimensional computational model is established to analyze the deformation.

The Current State of Silicone-Based Dielectric Elastomer Transducers

“…Their major disadvantage is that they require high driving voltages to actuate (typically 500 V to 10 kV), and so a great deal of research focuses on reducing this issue. Electronic EAPs can be divided further into subclasses, such as polymer electrets, electrostrictive graft elastomers and dielectric elastomers. In the field of electronic EAPs, dielectric elastomers are a very interesting class of material, due to high obtainable actuation speeds, large strains and high work densities, a high degree of electromechanical coupling and good overall performance .…”

Electrostrictive Polymer Nanocomposites: Fundamental and Applications

“…These dipole moments will rotate to align with the external electric field and therefore stimulate backbone chain reorientation and induce a much larger electrostrictive strain than neat PU. (Wang et al, 2004) Figure 7.6 Illustrative structure of the electrostrictive graft elastomer. (Wang et al, 2004) Another example can be the dielectric elastomer gel.…”

Applications of Electroactive Polymers: Review

“…Electrostrictive EAPs consist of partial charges which rotate upon the application of the electric field. This causes an electrostriction effect 10 . In Ionic polymers, the actual flow of ions takes place.…”