Large stiffness thermoformed open cell foams with auxeticity

Qicheng Zhang*, Wenjiang Lu, Fabrizio Scarpa, David Barton, Roderick S Lakes, Yunpeng Zhu, Ziqiang Lang, Hua-Xin Peng*

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

21 Citations (Scopus)
80 Downloads (Pure)


Open cell foams with auxeticity and modulus 5 times larger than the stiffest auxetic polymeric open cell foam featured in scientific literature are developed in this paper by using vacuum bags and autoclave following a thermoforming process. The resulting foam is transverse isotropic with microstructures exhibiting elongated semi-reticulated configurations, and contains a plane in which the auxetic behavior is evident. Tensile and compression quasi-static tests were carried out on samples cut along different directions and with different thicknesses. Foams have been also subjected to tensile training at different maximum strains to assess their mechanical performance. The tensile modulus and Poisson’s ratio values of the auxetic foams produced in this work can reach 25MPa and 0.4 in one plane and can feature a negative Poisson’s ratio up to -1.3 for thinner specimens. Smaller thicknesses and higher tensile training strains can also reduce the stiffness but enhance the auxeticity of this porous material.
Original languageEnglish
Article number100775
Number of pages14
JournalApplied Materials Today
Early online date30 Jul 2020
Publication statusPublished - 1 Sept 2020

Structured keywords

  • Engineering Mathematics Research Group


  • auxetic
  • thermoformed foam
  • negative Poisson's ratio
  • modulus
  • loss factor


Dive into the research topics of 'Large stiffness thermoformed open cell foams with auxeticity'. Together they form a unique fingerprint.

Cite this