4D Printing of Programmable Digital Metamaterials

Abstract: Advances in 3D printing technology now enable the precise positioning of microscopic material voxels to form complex structures. Combined with emerging multi-material capabilities and printable responsive materials, this opens new possibilities for digital composite materials and 3D printing of shape-transforming structures, or 4D printing. Building upon these advancements, we devise a novel methodology for crafting digitized 4D-printed shape-transforming sheets. We 3D print responsive sheets composed of two layers, each consisting of active and passive voxels meticulously positioned to form thin structures that can be actuated on demand. Our approach solves a long-standing problem in the field, i.e., the independent and simultaneous programming of lateral geometry and reference curvature. This unprecedented control over the resulting shape unlocks new opportunities in synthetic shape-morphing materials, with potential applications in programmable mechanical properties and multi-material systems.