title: Harnessing buckling to design tunable locally resonant acoustic metamaterials.
abstract: We report a new class of tunable and switchable acoustic metamaterials comprising resonating units dispersed into an elastic matrix. Each resonator consists of a metallic core connected to the elastomeric matrix through elastic beams, whose buckling is intentionally exploited as a novel and effective approach to control the propagation of elastic waves. We first use numerical analysis to show the evolution of the locally resonant band gap, fully accounting for the effect of nonlinear pre-deformation. Then, we experimentally measure the transmission of vibrations as a function of the applied loading in a finite-size sample and find excellent agreement with our numerical predictions. The proposed concept expands the ability of existing acoustic metamaterials by enabling tunability over a wide range of frequencies. Furthermore, we demonstrate that in our system the deformation can be exploited to turn on or off the band gap, opening avenues for the design of adaptive switches.
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Pai
authors.initials: P
authors.lastname: Wang
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Filippo
authors.initials: F
authors.lastname: Casadei
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Sicong
authors.initials: S
authors.lastname: Shan
authors.affiliation: Wyss Institute for Biologically Inspired Engineering, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: James C
authors.initials: JC
authors.lastname: Weaver
authors.affiliation: School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA and Kavli Institute, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Katia
authors.initials: K
authors.lastname: Bertoldi
mesh_terms: D000162:Acoustics / Q000295:instrumentation*; D008962:Models, Theoretical; D012825:Silicon / Q000737:chemistry; D013016:Sound
chemical_list: D012825:Silicon