Single-Layer 4D Printing System Using Focused Light: A Tool for Untethered Microrobot Applications

Four-dimensional (4D) printing is a promising technique that can produce shape-morphing materials to designated stimuli. However, as bilayered structures with varying mechanical properties are required in conventional methods, structural limitations—such as thickness or curvature of the structure—have hindered the application of 4D printing technology. Herein, we demonstrate a novel single-layer 4D printing system using focused light (SPROUT)...