3D cubic buckling mechanical metamaterials

Abstract

Current concepts for shock absorbers are based on destructive deformation or viscoelasticity. In the latter case the absorbers are reusable but the amount of absorbed energy heavily depends on the loading speed. Frenzel et al. have introduced a concept using buckling mechanical instabilities to realize a reusable shock absorber working independently of the loading conditions [1]. They presented proof-of-principle structures with a uniaxial hexagonal lattice, being able to absorb shocks along this axis. We extend this idea to a cubic structure, being able to absorb energy from shocks of any direction. The structure is fabricated using three-dimensional direct-laser writing. The produced samples show energy absorption along all axes probed, including the principal axes. Unfortunately, it turns out, that the viscoelasticity of the used photoresist is quite large. Hence, we cannot observe the predicted effect in our samples.