This talk discusses recent developments in the quest to model complex physical phenomena where multiple length and time scales need to be treated. In particular, materials modelling from the atomic-scale interactions to macroscopic continua is highlighted from the point of view of computational science. As a specific example, the case of three-dimensional etching of silicon-based microelectromechanical (MEM) components is presented. Moreover, the parallelisation of real-space-based methods for modelling nanostructures is discussed.