Electroactuation of solvated triblock copolymer dielectric elastomers: Decoupling the roles of mechanical prestrain and specimen thickness

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 49; no. 22; pp. 1569 - 1582
• Main Authors: Krishnan, Arjun S., Vargantwar, Pruthesh H., Ghosh, Tushar K., Spontak, Richard J.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 15.11.2011; Wiley
• Subjects: Applied sciences; biaxiality; Block copolymers; Decoupling; Devices; dielectric properties; Dielectrics; Elastomers; Electric fields; Electroactive polymers; Exact sciences and technology; gels; mechanical properties; micelles; modulus; Organic polymers; Physicochemistry of polymers; Properties and characterization; self-assembly; Solution and gel properties; stimuli-responsive polymers; Transducers; Deformation; Film; SEBS; Mineral oil; Disruptive voltage; gels; Size effect; stimuli-responsive polymers; modulus; Actuator; block copolymers; films; Stress strain relation; dielectric properties; Mechanical properties; Physical gel; Thermoplastic rubber; Experimental study; micelles; self-assembly; Compressive stress; Concentration effect; biaxiality; Electric field effect; Bulk modulus; Electromechanical properties
• ISSN: 0887-6266; 1099-0488; 1099-0488
• DOI: 10.1002/polb.22331

Dielectric elastomers (DEs) constitute a class of electroactive polymers that are becoming increasingly important as lightweight and mechanically robust replacements for conventional transducers and actuators. Because of their inherent cycling resilience, they also show tremendous promise as energy‐harvesting media, as well as smart sensors and microfluidic devices. Recent studies have demonstrated that DEs composed of midblock‐solvated triblock copolymers exhibit attractive electromechanical attributes such as giant electroactuation strains at relatively low electric fields at high conversion efficiency. Moreover, the properties of these readily processable systems are highly composition‐tunable, thereby making them ideal candidates for a detailed study of the coupling between initial specimen thickness and mechanical prestrain, which is frequently used to reduce specimen thickness before actuation to lower the voltage required to achieve electroactuation. Conventional wisdom based on the notion of an ideal DE indicates that electroactuation should only depend on pre‐actuation specimen thickness, but we report results that unequivocally indicate a more detailed material/process description is required. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1569–1582, 2011 Electroactive polymers show tremendous promise in many future technologies, from robotics and sensors to sustainable energy sources and energy harvesting. At a constant electric field, the electromechanical properties of an ideal dielectric elastomer are not expected to vary substantially. Using selectively solvated triblock copolymers it is shown here that, to the contrary, the properties depend on the coupling of prestrain and specimen thickness, indicating that the role of material properties on electroactuation attributes requires greater understanding.