RT Journal Article
SR Electronic
T1 Ultralight, ultrastiff mechanical metamaterials
JF Science
JO Science
FD American Association for the Advancement of Science
SP 1373
OP 1377
DO 10.1126/science.1252291
VO 344
IS 6190
A1 Zheng, Xiaoyu
A1 Lee, Howon
A1 Weisgraber, Todd H.
A1 Shusteff, Maxim
A1 DeOtte, Joshua
A1 Duoss, Eric B.
A1 Kuntz, Joshua D.
A1 Biener, Monika M.
A1 Ge, Qi
A1 Jackson, Julie A.
A1 Kucheyev, Sergei O.
A1 Fang, Nicholas X.
A1 Spadaccini, Christopher M.
YR 2014
UL http://science.sciencemag.org/content/344/6190/1373.abstract
AB Framework or lattice structures can be remarkably strong despite their very low density. Using a very precise technique known as projection microstereolithography, Zheng et al. fabricated octet microlattices from polymers, metals, and ceramics. The design of the lattices meant that the individual struts making up the materials did not bend under pressure. The materials were therefore exceptionally stiff, strong, and lightweight.Science, this issue p. 1373 The mechanical properties of ordinary materials degrade substantially with reduced density because their structural elements bend under applied load. We report a class of microarchitected materials that maintain a nearly constant stiffness per unit mass density, even at ultralow density. This performance derives from a network of nearly isotropic microscale unit cells with high structural connectivity and nanoscale features, whose structural members are designed to carry loads in tension or compression. Production of these microlattices, with polymers, metals, or ceramics as constituent materials, is made possible by projection microstereolithography (an additive micromanufacturing technique) combined with nanoscale coating and postprocessing. We found that these materials exhibit ultrastiff properties across more than three orders of magnitude in density, regardless of the constituent material.