Evaluation for the actuation performance of dielectric elastomer actuator using polyisoprene elastomer with dynamic ionic crosslinks

The dielectric properties of self-healing dynamic ion crosslink (DIC) elastomer and its performance as a dielectric elastomer actuator (DEA) were evaluated. The relative permittivity of the DIC elastomer was approximately 3.0 and it was almost constant in the frequency range of 20-200,000 Hz and in the field strength below 2.70 V/mu m at 20 Hz. The expected large-scale ionic polarization of the ionic aggregates was not observed under the electric field examined. The maximum blocking stress of the DEA using the DIC elastomer (DIC-DEA) was much larger (approximately 22.6 times) than that of the DEA using a commercial tape (VHB4910) (VHB-DEA). This is brought by the advantage that the breakdown strength of DIC-DEA is much higher than that of VHB-DEA. The Young's modulus of DIC showed a peculiar behavior; it was higher (1.4 times) under an electric field (3.00 V/mu m) than in the absence of an electric field (0.39 +/- 0.07 MPa). The maximum blocking stress at 1.0 kV/s was the same as that at 0.2 kV/s. This would reflect the fact that the blocking stress is independent of the Young's modulus as a function of the deformation rate. In addition, cut DIC elastomer reconnected at room temperature, and the blocking stresses at 5.80 V/mu m of the self-healed DIC-DEA was the same as that of the prior-to-cut DIC-DEA, regardless of the rate of change of voltage. These results suggest that DIC-DEA is a sustainable DEA that exhibits no deterioration of the performance because of its self-healing behavior even after the mechanical damage. (c) 2021 Elsevier B.V. All rights reserved.