Voxel design of additively manufactured digital material with customized thermomechanical properties

Spatial control of material properties is highly desirable in additive manufacturing of functional structures with complex geometries. Whereas most previous efforts focused on developing new printing or material systems, we propose a new voxel design strategy of constructing digital materials to provide the additively manufactured polymeric structures with spatially customized thermomechanical properties. In our approach, a matrix-inclusion composite layout is adopted in the linearly patterned voxels that perform as building blocks to construct bulk material. Through rational design of voxel size and inclusion content, the printed polymeric digital material displays a tunable storage modulus up to three orders of magnitude and glass transition temperature ranging from 0 °C to 60 °C. By taking advantage of the design freedom, we demonstrate a sequential folding structure with spatially tunable actuation speed, and multi-stable configurations that trap elastic energy in deterministic collapse sequences. Overall, our approach provides an effective and convenient way of spatially customizing material properties for additive manufacturing and offers instructive inspirations to the realm of digital fabrication.