Cauchy continuum-based theories typically employed to model conventional solids may not be able to capture the complex or exotic behaviour of certain materials. In particular, materials exhibiting size effects or atypical mechanical behaviour, like architected materials, metamaterials, and materials undergoing rather complex microscopic phenomena, require models that include additional information concerning their microstructure, such as generalised continua theories and multi-scale approaches. This mini-symposium provides a place for discussion and exchange of ideas regarding the modelling, design and analysis of materials, taking into account their microstructure and their (possibly) non-classical behaviour at different scales. On the one hand, recent advances on the numerical description of this class of materials are foreseen, with focus on the multi-scale modelling through homogenisation schemes, techniques for optimal design of macro or microstructure and constitutive modelling based on generalised continua (Cosserat, micromorphic, strain gradient, ...). On the other hand, there is also place to share the applications and potential industrial transference of this sort of techniques to specific classes of materials, like metamaterials, fibre reinforced composites, polycrystalline materials, biological structures, and architected materials, not to be exhaustive. Contributions addressing but not limited to the topics listed in what follows are welcomed: - Multi-scale models based on homogenisation of standard or generalised continua; - Modelling of size effects, fracture and damage across the scales; - Reduced-order and surrogate models for multi-scale and/or generalised continua; - Constitutive modelling and parameters calibration in generalised continua; - Multi-scale design and optimisation of high-performance materials and metamaterials; - Numerical methods to solve generalised continua and multi-scale problems; - Industrial multiscale analysis of complex and high performance engineering materials.