Giant, voltage-actuated deformation of a dielectric elastomer under dead load

Abstract

Far greater voltage-actuated deformation is achievable for a dielectric elastomer under equal-biaxial dead load than under rigid constraint usually employed. Areal strains of 488% are demonstrated. The dead load suppresses electric breakdown, enabling the elastomer to survive the snap-through electromechanical instability. The breakdown voltage is found to increase with the voltage ramp rate. A nonlinear model for viscoelastic dielectric elastomers is developed and shown to be consistent with the experimental observations.

Improved electromechanical behavior in castable dielectric elastomer actuators

“…When a voltage is applied to the electrodes, the membrane is squeezed in thickness and expands in plane due to the electrostatic pressure. Giant voltagetriggered deformations up to 360% linear strain with clamped elastomer, 5 488% area strain with membrane under dead loads, 6 and 1692% area strain on membranes mounted on an air chamber 7 have been reported using polyacrylate VHB films from 3 M. However, to achieve reproducible and fast actuation and to prevent creep phenomenon, one must switch from VHB to materials with negligible viscoelastic behavior such as some classes of polydimethylsiloxanes (PDMS) or polyurethanes. Pelrine et al have reported, in 2000, a 117% uniaxial linear strain with an actuator patterned as a long strip on a uniaxially prestretch silicone elastomer.…”

Maximizing the Energy Density of Dielectric Elastomer Generators Using Equi‐Biaxial Loading

“…The mechanical loading configuration was modified from that in our previous work on actuators [11] . Equi-biaxial loading was accomplished by applying radial forces to the circumference of the DE sheet through an assembly of clips, wires (0.23 mm, 1080 carbon steel) and pulleys, all loaded by the motion of a linear servo-motor (Model SLP35, Nippon Pulse America Inc.), which is schematically shown in Figure 1a Figure 1c and 1d, respectively.…”

Large, uni-directional actuation in dielectric elastomers achieved by fiber stiffening

“…While large voltage-induced deformation has been demonstrated for an elastomer sheet under equal-biaxial forces, [24][25][26] only small voltage-induced deformation has been observed for an elastomer sheet under a uniaxial force. 27 Many applications, however, require muscle-like actuators in which a voltage induces large and unidirectional displacement.…”