The main objective of the Workshop is to gather scientists (experimentalists and theoreticians) from the EU, newly associate countries and other countries, in one place to exchange information on new experimental and theoretical results and methods in the field of materials of unusual mechanical (elastic, viscoelastic, thermoelastic, etc) properties (materials of negative Poisson’s ratio, materials with negative stiffness inclusions, systems of extreme hardness, etc). Exchange of information and ideas may lead to the formulation of directions for new research activities on such systems. The Workshop is also addressed to young scientists (students, Ph.D. students and post-docs), with the aim of acquainting them with theoretical, experimental and simulation methods used in the physics of such systems.