Hierarchical supramolecules composed of starch-based nanocluster aggregates with light-responsive mechanical strain...

Hierarchical supramolecular systems, characterized by nanoscale sensitivity and macroscopic tangible changes, offer promising perspectives for the design of remotely controllable, rapid, and precise actuation materials, serving as a potential substitution for non-intelligent and complex actuation switches. Herein, we reported on the disassembly of orderly and rigid starch helical covalent structures, and their subsequent reassembly into a hierarchical supramolecular gel composed of nanocluster aggregates, integrating supramolecular interactions of three different scales. The incorporation of photo-sensitive Fe^IIITA, a complex of trivalent iron ions and tannic acid, significantly enhances the photo-responsive strain capacity of the hierarchical supramolecular gel. The supramolecular gel exhibits its features in a rapid light-responsive rate of hardness and viscosity, enabling the actuation of objects within 22 s under light exposure when employed as a remote actuation switch. Meanwhile, this actuation mechanism of the hierarchical supramolecular gel also has a promising perspective in precise control, identifying and actuating one of the two objects in distances of 0.8 mm even smaller scales. Our work provides a reliable reference for replacing complex actuation switches with intelligent materials for remote, rapid, and accurate actuation, and offers valuable insights for actuation in harsh and vacuum outdoor environments.