Kostas Danas holds a tenured position as a CNRS Director of Research (Directeur de Recherche) and Professor at the Solid Mechanics Laboratory (LMS), Department of Mechanics at Ecole Polytechnique, where he teaches courses on continuum and fracture mechanics. His research focuses on the numerical, theoretical and experimental analysis of microstructured active elastomers and their instabilities as well as on the modelling and fracture of metallic and 3D printed polymeric porous materials. Oscar Lopez-Pamies holds PhD degrees in Mechanical Engineering and Applied Mechanics from the University of Pennsylvania (USA) and the École Polytechnique (France). He is currently the Colonel Harry F. & Frankie M. Lovell Endowed Professor at the University of Illinois Urbana-Champaign, where he teaches graduate and undergraduate courses on the mechanics of solids, constitutive modeling, homogenization, and numerical methods for PDEs. His research focuseson the development of mathematical theories and associated numerical methods to describe, explain, and predict the mechanical and physical behavior, stability, and failure of solids.