Soft Actuator Based on Metal/Hydrogel Nanocomposites with Anisotropic Structure

Abstract

Abstract The controlling of anisotropic structure in smart hydrogels is essential to fabricate hydrogel‐based soft actuators. Herein, a facile strategy to fabricate smart hydrogel with controllable anisotropic structure and the corresponding deformability is proposed. Poly( N ‐isopropylacrylamide) (PNIPAM) hydrogel is fabricated as actuator by asymmetric growth of silver (Ag) microdendrite structures in the hydrogel matrix through a phototriggered electroreduction. The existence of Ag microdendrite structures at specific area in hydrogel changes the swelling/shrinking rates of the related region, which driving the deformation behavior of the hydrogel. By adjusting the electroreduction parameters and the patterns on the reducing electrode, distribution of Ag microstructures both along the vertical and lateral direction in hydrogel matrix can be precisely controlled, which further enables designed deformations of the hydrogel nanocomposites. As a result, various soft actuators such as bending beam, gripper, and flower‐shaped actuator are designed, and the temperature triggered actions of these actuators, such as curling and gripping are realized.