title: Elastic metamaterials for independent realization of negativity in density and stiffness.
abstract: In this paper, we present the first realization of an elastic metamaterial allowing independent tuning of negative density and stiffness for elastic waves propagating along a designated direction. In electromagnetic (or acoustic) metamaterials, it is now possible to tune permittivity (bulk modulus) and permeability (density) independently. Apparently, the tuning methods seem to be directly applicable for elastic case, but no realization has yet been made due to the unique tensorial physics of elasticity that makes wave motions coupled in a peculiar way. To realize independent tunability, we developed a single-phased elastic metamaterial supported by theoretical analysis and numerical/experimental validations.
authors.affiliation: Institute of Advanced Machine and Design, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Korea.
authors.forename: Joo Hwan
authors.initials: JH
authors.lastname: Oh
authors.affiliation: Korea Institute of Nuclear Safety, 62 Gwahak-ro, Yuseoung-gu, Daejeon 305-338, Korea.
authors.forename: Young Eui
authors.initials: YE
authors.lastname: Kwon
authors.affiliation: Department of Mechanical and Aerospace Engineering, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Korea.
authors.forename: Hyung Jin
authors.initials: HJ
authors.lastname: Lee
authors.affiliation: Institute of Advanced Machine and Design, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Korea.|Department of Mechanical and Aerospace Engineering, 599 Gwanak-ro, Gwanak-gu, Seoul, 151-744, Korea.
authors.forename: Yoon Young
authors.initials: YY
authors.lastname: Kim