Mechanical metamaterials are an emerging class of materials primarily governed by their architecture to create lightweight materials with extreme mechanical properties. The functionality of such materials is limited by their tolerance to damage and defects, better known as "fracture toughness." Materials scientists credit the difficulty in part to the manufacture and characterization of a large number of unit cells. In a recent report now published on Nature Materials, Angkur Jyoti Dipanka Shaikeea and a team of scientists in engineering and metamaterials at the University of Cambridge U.K., and the University of California, Los Angeles, U.S., combined numerical and asymptotic analyses to extend the ideas of elastic fracture mechanics to mechanical 3D metamaterials and developed a design protocol to form optimally robust discrete solids.
