  The insurgence of compression induces wrinkling in actuation devices based on
EAPs thin films leading to a sudden decrease of performances up to failure.
Based on the classical tension field theory for thin elastic membranes, we
provide a general framework for the analysis of the insurgence of in-plane
compression in membranes of electroactive polymers (EAPs). Our main result is
the deduction of a (voltage-dependent) domain in the stretch space which
represents tensile configurations. Under the assumption of Mooney-Rivlin
materials, we obtain that for growing values of the applied voltage the domain
contracts, vanishing at a critical voltage above which the polymer is wrinkled
for any stretch configuration. Our approach can be easily implemented in
numerical simulations for more complex material behaviors and provides a tool
for the analysis of compression instability as a function of the elastic
moduli.
