Environmentally friendly shape memory smart composite material with multiple response modes

Cellulose and lignin offer advantages of low cost and environmental friendliness. In this study, a multi-responsive shape memory smart composite material was proposed based on carboxymethyl cellulose and lignin. Lignin imparts photothermal responsiveness to the composite, while cellulose provides water responsiveness. A bio-inspired structure mimicking the water transport mechanism of plant leaves was developed to improve the water responsive functionalities of composite material (shape recovery within 30 s). A self-driven device that mimics the blooming of a flower was successfully fabricated using this composite material. The shape memory smart composite material exhibits a high degree of design flexibility. Based on the mechanisms of water response, a simple structure programming method was proposed, enabling the design of programmable structures with smart and controllable features. This study provides a new approach to the design of multifunctional smart materials, enhancing the application potential of shape memory materials under multiple environmental factors.