Auxetic materials: Avoiding the shrink (original) (raw)

• Concepts
• Published: 16 October 2003

Nature volume 425, page 667 (2003)Cite this article

• 3218 Accesses
• 138 Citations
• Metrics details

The Poisson ratio (defined as −1 times the ratio of lateral to applied elastic strains) describes the behaviour of stretched materials — positive Poisson ratios characterize the expected normal behaviour, whereas auxetic materials have a negative value. Although Poisson's ratio for cubic phases must be between −1 and +2, there is no theoretical limitation on this ratio for materials with less internal symmetry. Although few crystals have negative Poisson's ratios for all stretch and lateral directions, such behaviour can be obtained for foams of most materials.

The behaviour of some auxetic materials seems more fitting for Alice's Wonderland than for the real world. After an initial elongation, stretching the porous polytetrafluoroethylene used as artificial arteries generates up to an 11-fold higher relative expansion in one lateral direction. Although the direct effect of a negative Poisson's ratio is to cause an expansion that decreases density during stretching, a small fraction of auxetic crystals actually increase in density when stretched. This behaviour is quite rare, but all 13 observed stretch-densified crystals (out of 500 investigated crystals) are auxetic.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

• Hinged-3D metamaterials with giant and strain-independent Poisson’s ratios

  • Mohamed Shaat
  • & Ahmed Wagih
    Scientific Reports Open Access 10 February 2020

• Shape-matching soft mechanical metamaterials

  • M. J. Mirzaali
  • , S. Janbaz
  • … A. A. Zadpoor
    Scientific Reports Open Access 17 January 2018

Access options

Subscribe to this journal

Receive 51 print issues and online access

$199.00 per year

only $3.90 per issue

Buy this article

• Purchase on SpringerLink
• Instant access to full article PDF

Prices may be subject to local taxes which are calculated during checkout

Additional access options:

• Log in
• Learn about institutional subscriptions
• Read our FAQs
• Contact customer support

Author information

Authors and Affiliations

1. NanoTech Institute and Department of Chemistry, University of Texas, Dallas, Richardson, 75083-0688, Texas, USA
   Ray H. Baughman

Rights and permissions

About this article

Cite this article

Baughman, R. Auxetic materials: Avoiding the shrink.Nature 425, 667 (2003). https://doi.org/10.1038/425667a

Download citation

• Issue Date: 16 October 2003
• DOI: https://doi.org/10.1038/425667a

This article is cited by