Bio-inspired shape-memory structural color hydrogel film

Structural colors, derived from existing natural creatures, have aroused widespread attention in the materials regulation for different applications. Here, inspired by the color adjusting mechanism of hummingbird, we present a novel shape-memory structural color hydrogel film by introducing shape memory polymers (SMPs) into synthetic inverse opal scaffold structure. The excellent flexibility as well as the inverse opal structure of the hydrogel films imparts them with stable stretchability and brilliant structural colors. Benefiting from the transient structural anisotropy of copolymers, the hybrid films are possessed with shape-morphing behaviors capability. Based on the shape transformations and color responsiveness performance, we have demonstrated diverse structural color actuators with complex shapes for different tasks. Notably, as the photothermal responsive graphene quantum dots were integrated into the hydrogel, the hybrid films could also be endowed with the feature of light-controlled reversible deformation with synchronous structural color variation. These features demonstrate that the presented shape-memory structural color hydrogel film is valuable for soft robotics with multi functions of sensing, communication and disguise.(c) 2021 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.

Automated summary

Inspired by the color adjusting mechanism of hummingbird, researchers have developed a shape-memory hydrogel film with structural colors. The film exhibits excellent flexibility and stable stretchability, and possesses shape-morphing behaviors capability. By integrating photothermal responsive graphene quantum dots, the film also shows light-controlled reversible deformation with synchronous structural color variation. This shape-memory structural color hydrogel film holds great potential for applications in soft robotics.