Relationship between electric current and matrix modulus in electrorheological elastomers

We have carried out a series of tests on electrorheological elastomers, whi ch consist of semi-conducting solid particles dispersed in a low-conductivi ty silicone-based elastomer, with the investigations focussing on the depen dence of the DC electric current on the elastomer modulus. We find that whe n other conditions are held constant, the electric current under a particul ar electric field shows a significant decrease when an elastomer of higher modulus is used. This behaviour is explained qualitatively using a simple m odel based on the mechanical equilibrium of two competing forces: the elect rostatic attraction force between the two adjacent particles in the field d irection, and the elastic squeezing force due to the elastomer between the particles which resists their approach. (C) 2001 Elsevier Science B.V. All rights reserved.