Kollosche, MatthiasKofod, GuggiSuo, ZhigangZhu, Jian2015-02-032015Kollosche, Matthias, Guggi Kofod, Zhigang Suo, and Jian Zhu. 2015. “Temporal Evolution and Instability in a Viscoelastic Dielectric Elastomer.” Journal of the Mechanics and Physics of Solids 76 (March): 47–64. doi:10.1016/j.jmps.2014.11.013.0022-5096http://nrs.harvard.edu/urn-3:HUL.InstRepos:13910327Dielectric elastomer transducers are being developed for applications in stretchable electronics, tunable optics, biomedical devices, and soft machines. These transducers exhibit highly nonlinear electromechanical behavior: a dielectric membrane under voltage can form wrinkles, undergo snap-through instability, and suffer electrical breakdown. We investigate temporal evolution and instability by conducting a large set of experiments under various prestretches and loading rates, and by developing a model that allows viscoelastic instability. We use the model to classify types of instability, and map the experimental observations according to prestreches and loading rates. The model describes the entire set of experimental observations. A new type of instability is discovered, which we call wrinkle-to-wrinkle transition. A flat membrane at a critical voltage forms wrinkles and then, at a second critical voltage, snaps into another state of winkles of a shorter wavelength. This study demonstrates that viscoelasticity is essential to the understanding of temporal evolution and instability of dielectric elastomers.en-USDielectric elastomerViscoelasticitySnap-through instabilityPhase transitionWrinklingJournal Article2015-01-25Matthias Kollosche, Guggi Kofod, Zhigang Suo, Jian Zhu2015-02-0310.1016/j.jmps.2014.11.013