Double-Negative Mechanical Metamaterials Displaying Simultaneous Negative Stiffness and Negative Poisson's Ratio Properties

Trishan A M Hewage; Kim L Alderson; Andrew Alderson; Fabrizio Scarpa

doi:10.1002/adma.201603959

Double-Negative Mechanical Metamaterials Displaying Simultaneous Negative Stiffness and Negative Poisson's Ratio Properties

Adv Mater. 2016 Dec;28(46):10323-10332. doi: 10.1002/adma.201603959. Epub 2016 Oct 26.

Authors

Trishan A M Hewage¹, Kim L Alderson², Andrew Alderson¹, Fabrizio Scarpa³

Affiliations

¹ Materials and Engineering Research Institute, Faculty of Arts, Computing, Engineering and Sciences, Sheffield Hallam University, Howard Street, Sheffield, S1 1WB, UK.
² 72 Phillips Lane, Formby, Liverpool, L37 4BQ, UK.
³ Advanced Composites Centre for Innovation and Science, University of Bristol, University Walk, Bristol, BS8 1TR, UK.

PMID: 27781310
DOI: 10.1002/adma.201603959

Abstract

A scalable mechanical metamaterial simultaneously displaying negative stiffness and negative Poisson's ratio responses is presented. Interlocking hexagonal subunit assemblies containing 3 alternative embedded negative stiffness (NS) element types display Poisson's ratio values of -1 and NS values over two orders of magnitude (-1.4 N mm^-1 to -160 N mm^-1 ), in good agreement with model predictions.

Keywords: auxetic; mechanical metamaterials; mechanical properties; negative Poisson's ratio; negative stiffness.