Electromechanical Interplay in Deformable Dielectric Elastomer Networks

A systematic, statistical-mechanics-based analysis of the response of dielectric elastomers to coupled electromechanical loading is conducted, starting from the monomer level through the polymer chain and ending with closed-form expressions for the polarization and stress fields. It is found that the apparent response at the macrolevel is dictated by four microscopic parameters—the monomer type and polarizability and the chain length and density. Our analysis further reveals a new electrostrictive effect that either reinforces or opposes the polarization-induced deformation. The validity of the results is attested through comparisons with well-established experimental measurements of both the polarization field and the electrostrictive stress.

Figure 1

A DE layer in its (a) unloaded and (b) electromechanically loaded configurations.

Figure 2

Polymer chains with (a) uniaxial and (b) transversely isotropic monomers [13].

Figure 3

Normalized susceptibility versus deformation.

Figure 4

Stress versus electric field. Analytical predictions and experimental measurements of (a) Pelrine et al. [23], (b) Wissler and Mazza [20] and (c) Kofod and Sommer-Larsen [22].

Figure 5

Schematic description of the tendency of uniaxial dipoles to align along the electric field and the resulting forces on the end points of two chains whose end-to-end vectors are (a) along and (b) perpendicular to the electric field.