Three-dimensional architected materials and structures. Three-dimensional architected materials are a new class of materials culminating from the confl uence of new technologies. These materials show promise for multifunctional applications, combining a mechanical function (such as stiffness and strength) with some other property (such as thermal or electrical conductivity), thereby allowing for interesting applications such as structural batteries, structural armor, and deployable materials. These materials embody the characteristics of both the constituent material as well as the structure. The “woven” architectures on the cover were fabricated out of IP-Dip photoresist via twophoton lithography direct laser writing. Each strut is comprised of three interwoven spirals formed into a classical lattice shape. These materials exhibit superior tensile ductility in excess of 60%, after which they fully recover and can then be immediately compressed by more than 50% and recover fully. Image courtesy of Widianto P. Moestopo, California Institute of Technology, and inspired by Ritchie Fuller. See the technical theme that begins on p. 750.