title: Multiscale metallic metamaterials.
abstract: Materials with three-dimensional micro- and nanoarchitectures exhibit many beneficial mechanical, energy conversion and optical properties. However, these three-dimensional microarchitectures are significantly limited by their scalability. Efforts have only been successful only in demonstrating overall structure sizes of hundreds of micrometres, or contain size-scale gaps of several orders of magnitude. This results in degraded mechanical properties at the macroscale. Here we demonstrate hierarchical metamaterials with disparate three-dimensional features spanning seven orders of magnitude, from nanometres to centimetres. At the macroscale they achieve high tensile elasticity (>20%) not found in their brittle-like metallic constituents, and a near-constant specific strength. Creation of these materials is enabled by a high-resolution, large-area additive manufacturing technique with scalability not achievable by two-photon polymerization or traditional stereolithography. With overall part sizes approaching tens of centimetres, these unique nanostructured metamaterials might find use in a broad array of applications.
authors.affiliation: Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zheng
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: William
authors.initials: W
authors.lastname: Smith
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: Julie
authors.initials: J
authors.lastname: Jackson
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: Bryan
authors.initials: B
authors.lastname: Moran
authors.affiliation: Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Huachen
authors.initials: H
authors.lastname: Cui
authors.affiliation: Department of Mechanical Engineering, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Da
authors.initials: D
authors.lastname: Chen
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: Jianchao
authors.initials: J
authors.lastname: Ye
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Fang
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Rodriguez
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: Todd
authors.initials: T
authors.lastname: Weisgraber
authors.affiliation: Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Spadaccini