▎ 摘　　要

Recently, soft actuators made of electroactive materials that show fast environmental response, large deformation, and can mimic multifunctional actuation of living creatures have attracted considerable attention for a variety of applications including wearable electronics, microrobotic devices, and intelli-gent artificial muscles. In this study, we designed an electro-responsive hydrogel actuator system with high stretchability, good self-recovery, and fast electro-responsive actuation. We prepared a hydrogel with double network structure consisting of partially reduced graphene oxide (CRGO) with carboxylic groups, poly (acrylic acid) (PA), and Fe3+ ions. The partially reduced CRGO shows excellent dispersibility and stability in an aqueous solution. The CRGO-embedded PA/CRGO/Fe hydrogels synthesized by varying the content of CRGO, FeCl3.6H2O, and crosslinker exhibited more than 75% gel fraction and a relatively high equilibrium water content (EWC) of 80.0-95.0%. Particularly, PA/CRGO/Fe hydrogels with a dual crosslinked network structure showed high stretchability of more than 1,200% and excellent self-healing properties. The electro-responsive actuation of PA/CRGO/Fe hydrogel can be precisely controlled by varying the content of CRGO, electric field strength, and concentration of the electrolyte solution. By controlling these influencing factors, PA/CRGO/Fe hydrogels exhibited rapid bending actuation of more than 100 degrees within 1 min under an electric field. In vitro cytotoxicity results showed a relatively high cell viability of more than 97%, indicating that the prepared PA/CRGO/Fe hydrogels had no significant cyto-toxicity. Therefore, these PA/CRGO/Fe hydrogels could be a promising material for electro-responsive soft robot applications.(c) 2023 Elsevier Ltd. All rights reserved.