title: Strong, lightweight, and recoverable three-dimensional ceramic nanolattices.
abstract: Ceramics have some of the highest strength- and stiffness-to-weight ratios of any material but are suboptimal for use as structural materials because of their brittleness and sensitivity to flaws. We demonstrate the creation of structural metamaterials composed of nanoscale ceramics that are simultaneously ultralight, strong, and energy-absorbing and can recover their original shape after compressions in excess of 50% strain. Hollow-tube alumina nanolattices were fabricated using two-photon lithography, atomic layer deposition, and oxygen plasma etching. Structures were made with wall thicknesses of 5 to 60 nanometers and densities of 6.3 to 258 kilograms per cubic meter. Compression experiments revealed that optimizing the wall thickness-to-radius ratio of the tubes can suppress brittle fracture in the constituent solid in favor of elastic shell buckling, resulting in ductile-like deformation and recoverability.
authors.affiliation: Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
authors.forename: Lucas R
authors.initials: LR
authors.lastname: Meza
authors.affiliation: Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA.
authors.forename: Satyajit
authors.initials: S
authors.lastname: Das
authors.affiliation: Division of Engineering and Applied Science, California Institute of Technology, Pasadena, CA, USA. Kavli Nanoscience Institute, California Institute of Technology, Pasadena, CA, USA. jrgreer@caltech.edu.
authors.forename: Julia R
authors.initials: JR
authors.lastname: Greer