Auxetic materials deform in an unusual way when stretched or compressed. This unusual behavior enables different properties such as variable permeability, energy absorption, resistance to fracture, adaptability, and resistance to shear load. Due to these properties, auxetic materials can have various applications, including biomedical applications, crash protection, body armor, fashion, architecture, fasteners, sports equipment, and aerospace technologies. Current auxetic materials are mainly foam-like cellular materials composed of trusses, beams, or porous media. These auxetic materials usually have low stiffness and strength, and experience large deformation. It is not suitable to carry large mechanical loads, especially under extreme loading conditions. Therefore, new auxetic materials with higher resistance and efficient energy dissipation properties should be designed.


Technology Overview

Researchers at Northeastern designed auxetic multi-phase composites, which are different from the existing auxetic materials; the new designs are not porous and do not constitute trusses or beams. The auxetic effect is achieved via shear-induced displacement between two neighboring domains composed of two different phases. The new 3D tiled composites exhibit auxetic behavior in all three directions. The engineering advantages of this new design are three folds: (1) auxetic-induced impact resistance; (2) efficient energy dissipation through shear; (2) significantly increased shear-induced damping within the material. Therefore, the composites are very good candidates for resisting impact loads, mitigating vibrations, and providing robust mechanical support.


This technology provides a large degree of freedom in terms of geometry and materials. A family of 3D tiled composites can be designed, including both regular and irregular composites. The design strategy can also be easily extended to design functionally graded materials. In this way, the mechanical properties including, stiffness, strength, toughness, Poisson’s ratio, and damping can be tuned to achieve desired performance. Also, it can be made of small building blocks, and therefore can potentially reduce the manufacturing, storage, and transportation costs. The potential applications of this technology can be across different scales, including impact-resistant materials, seismic-resistant construction, and anti-vibration materials.



  • High stiffness
  • Efficient energy dissipation through shear
  • Increased adaptability through shear
  • Various geometry
  • Possibility of using different functionally graded materials
  • Cost-effectiveness



  • Biomedical
  • Aerospace
  • Defense
  • Construction
  • Smart textile



  • Licensing
  • Research collaboration
  • Commercial partner
Patent Information:
For Information, Contact:
Mark Saulich
Associate Director of Commercialization
Northeastern University
Yaning Li
Mechanical Metamaterials