The thickness and stretch dependence of the electrical breakdown strength of an acrylic dielectric elastomer

The performance of dielectric elastomer actuators is limited by electrical breakdown. Attempts to measure this are confounded by the voltage-induced thinning of the elastomer. A test configuration is introduced that avoids this problem: A thin sheet of elastomer is stretched, crossed-wire electrodes are attached, and then embedded in a stiff polymer. The applied electric field at breakdown, E _B, is found to depend on both the deformed thickness, h, and the stretch applied, λ. For the acrylic elastomer investigated, the breakdown field scales as E _B 51 h ^{- 0.25} λ ^0.63. The test configuration allows multiple individual tests to be made on the same sheet of elastomer.