Alignment of Janus Particles In Dielectric Elastomer Films and Their Effect On Mechanical Actuation

The ability of dielectric elastomers (DEs) to deform due to electrostatic interactions induced by external electrical fields has become the basis of newly designed actuators and sensors. The deformation, called compressive strain, is proportional to the overall dielectric constant of the DEs, which itself depends on the local dipole moments.

In the work presented here, Janus particles that carry a dipole moment due to their anisotropic surface are added into the DE system to enhance the local dipole moment of the DE. We observe that poly(ethylene glycol phenyl ether acrylate), p(EGPEA), films filled with gold-capped silica Janus particles are able to achieve a higher strain under a fixed, external electric field. In an attempt to enhance the overall value of dipole moment of the p(EGPEA) matrix the uncured composite is exposed to an external DC field during polymerization resulting in the alignment of the gold-capped Janus particles.

We will report on the fabrication, characterization and strain/electric field correlation of the p(EGPEA) matrix as a function of filler material and alignment. Preliminary data enable us to conclude that alignment of gold cap plays an important role in the electroactive response of our system. Further, the comparison of plain and Janus particle filled composite p(EGPEA) matrices shows a remarkable deformation (>10%) attributed to the polar nature of the injected filler material.