Estimation and validation of maxwell stress of planar dielectric elastomer actuators

In this paper, Maxwell stress of circular planar actuator at different applied voltages was estimated and then validated with the uniaxial compression test of three different dielectric elastomers (VHB, silicone and natural rubber). Pelrine's equation was revisited to estimate Maxwell stress which causes the actuation in the planar direction. More precise and accurate estimation of Maxwell stress could be made in this work by considering variation of dielectric constant with respect to frequency and pre-strain. Estimated Maxwell stress was validated through (i) out-of-plane strain or thickness strain obtained from measured area strain considering constant volume deformation, and (ii) out-of-plane mechanical compressive test results. The estimated Maxwell stress agrees well with the corresponding experimental compressive stress values for different pre-straining cases considered in this work.