Near-Infrared Light-Driven Shape-Morphing of Programmable Anisotropic Hydrogels Enabled by MXene Nanosheets.

Herein, we report near-infrared (NIR) light-driven shape-morphing of programmable MXene-containing anisotropic hydrogel actuators that are fabricated through in situ free-radical copolymerization of a judiciously designed MXene nanomonomer with thermosensitive hydrogel network. A low electric field (few V mm-1 ) was found to enable a spatial distribution of MXene nanosheets and hence introduce anisotropy into the hydrogel network. Programmable anisotropic hydrogel actuators were developed by controlling ITO electrode pattern, direct-current (DC) electric field direction and mask-assisted photopolymerization. As a proof-of-concept, we demonstrate NIR light-driven shape morphing of the MXene-containing anisotropic hydrogel into various shapes and devise a four-arm soft gripper that can perform distinct photomechanical functions such as grasping, lifting/lowering down and releasing an object upon sequential NIR light exposure.