Diffusive buckling fronts in cubic lattices

Materials under large compression will eventually break, bend, or buckle - behaviors typically considered undesirable. However, carefully architected materials can exploit these instabilities to achieve new mechanical functionality. Periodic lattices in particular provide lightweight platforms where local instabilities can dictate global responses, with applications in energy routing, vibration isolation, and impact mitigation.

Through experiments we uncover how buckling instabilities, triggered by compression, propagate through overdamped, three-dimensional printed cubic lattice structures and shape their macroscopic behavior. We classify different modes of failure - from global to (non-uniform) local buckling - and connect them to lattice geometry. By incorporating viscoelastic dissipation into a 3D-continuum description, we demonstrate that buckling fronts obey coupled reaction–diffusion equations. The diffusion and reaction coefficients, controlled by local geometry, material properties, and strain, enable quantitative predictions and steering of strain-driven instability fronts. Our findings thus establish a predictive, tunable, and experimentally validated framework for the control of mechanical instabilities in 3D, dissipative metamaterials.