title: Ultralight metallic microlattices.
abstract: Ultralight (<10 milligrams per cubic centimeter) cellular materials are desirable for thermal insulation; battery electrodes; catalyst supports; and acoustic, vibration, or shock energy damping. We present ultralight materials based on periodic hollow-tube microlattices. These materials are fabricated by starting with a template formed by self-propagating photopolymer waveguide prototyping, coating the template by electroless nickel plating, and subsequently etching away the template. The resulting metallic microlattices exhibit densities ρ ≥ 0.9 milligram per cubic centimeter, complete recovery after compression exceeding 50% strain, and energy absorption similar to elastomers. Young's modulus E scales with density as E ~ ρ(2), in contrast to the E ~ ρ(3) scaling observed for ultralight aerogels and carbon nanotube foams with stochastic architecture. We attribute these properties to structural hierarchy at the nanometer, micrometer, and millimeter scales.
authors.affiliation: HRL Laboratories Limited Liability Company, Malibu, CA 90265, USA. taschaedler@hrl.com
authors.forename: T A
authors.initials: TA
authors.lastname: Schaedler
authors.forename: A J
authors.initials: AJ
authors.lastname: Jacobsen
authors.forename: A
authors.initials: A
authors.lastname: Torrents
authors.forename: A E
authors.initials: AE
authors.lastname: Sorensen
authors.forename: J
authors.initials: J
authors.lastname: Lian
authors.forename: J R
authors.initials: JR
authors.lastname: Greer
authors.forename: L
authors.initials: L
authors.lastname: Valdevit
authors.forename: W B
authors.initials: WB
authors.lastname: Carter