Effect of percolation on the deformation of isotropic electrorheological elastomers under external electric fields

Abstract

In this study we investigate the influence of the filler's concentration with an emphasis on the percolation of particles on the field-induced deformation of isotropic, disc shaped electrorheological elastomers (EREs) with barium titanate filler. It was found that above the percolation threshold concentration (>34.7 wt%) the magnitude of the fully reversible contraction was enhanced by a factor of ∼10 in the low field strength region (E≈ 0.2 MVm−1). At higher field strength (E= 1.1 MVm−1) the percolation had no effect on the induced strain, and regardless of the particle's concentration it saturated around 1.2%. It was shown that for isotropic EREs the optimal particle loading is just above the percolation threshold. If the filler content exceeds the threshold concentration, then the same deformation can be achieved with much lower field intensity, but even larger particle concentration does not enhance the performance further.