Actuation response of polyacrylate dielectric elastomers

G. Kofod, R. Kornbluh, R. Pelrine, P. Sommer-Larsen

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    Polyacrylate dielectric elastomers have yielded extremely large strain and elastic energy density suggesting that they are useful for many actuator applications. A thorough understanding of the physics underlying the mechanism of the observed response to an electric field can help develop improved actuators. The response is believed to be due to Maxwell stress, a second order dependence of the stress upon applied electric field. Based on this supposition, an equation relating the applied voltage to the measured force from an actuator was derived. Experimental data fit with the expected behavior, though there are discrepancies. Further analysis suggests that these arise mostly from imperfect manufacture of the actuators, though there is a small contribution from an explicitly electrostrictive behavior of the acrylic adhesive. Measurements of the dielectric constant of stretched polymer reveal that the dielectric constant drops, when the polymer is strained, indicating the existence of a small electrostrictive effect. Finally, measurements of the electric breakdown field were made. These also show a dependence upon the strain. In the unstrained state the breakdown field is 20 WV/m, which grows to 218MV/m at 500% x 500% strain. This large increase could prove to be of importance in actuator design.
    Original languageEnglish
    Title of host publicationSmart structures and materials 2001: Electroactive polymer actuators and devices
    EditorsY. Bar-Cohen
    Place of PublicationBellingham, WA
    PublisherInternational Society for Optical Engineering
    Publication date2001
    ISBN (Print)0-8194-4015-9
    Publication statusPublished - 2001
    EventAnnual international symposium on Smart Structures and Materials - Newport Beach, CA, United States
    Duration: 5 Mar 20018 Mar 2001
    Conference number: 8


    ConferenceAnnual international symposium on Smart Structures and Materials
    CountryUnited States
    CityNewport Beach, CA
    SeriesSPIE Proceedings Series, 4329

    Cite this

    Kofod, G., Kornbluh, R., Pelrine, R., & Sommer-Larsen, P. (2001). Actuation response of polyacrylate dielectric elastomers. In Y. Bar-Cohen (Ed.), Smart structures and materials 2001: Electroactive polymer actuators and devices (pp. 141-147). International Society for Optical Engineering. SPIE Proceedings Series, 4329