The need for high performance materials has led the way to seamless integration of multiple material components based on desirable properties. The development of nanocomposites and nanostructures opens the possibility for new materials with remarkable performance in comparison with the classical engineered materials, enabling the integration of both structure and material across multiple scales, due to complementary and synergistic interactions – i.e. compatibility – of the nanoscale components. The delivery, monitoring, behavior and control of nanostructures are important issues in the design of the next generation of structural materials, including cross-material interface compatibility and cooperativity, which can serve to amplify (or repress) specific material responses. These complex materials structures require multi-scale and/or multi-physics approach to connect structure to properties and ultimately to function. The unique amalgamation of the discrete multiple length spectrum and its multi-physics principles creates an unprecedented way to study the mechanism of nanocomposites through the marriage of advancement of theoretical studies, exploitation of computational methods, and non-traditional experimental validation. In particular, we are interested in the underlying mechanical and functional roles of multi-phase materials. This mini symposium welcomes contributions within this broad theme.