Materials modelling, i.e., formulation, implementation and application of theoretical models in materials research is a research area undergoing rapid development. This report gives a birds eye view of this area, with the purpose to define the term materials modelling, and to show how the research at FOI, especially research in the area of sensor applications, can be strengthened by the use of materials modelling. An introduction and general background to materials modelling is followed by a presentation of a few specific defence applications and how research related to these can be reinforced by the use of materials modelling. A brief overview of current materials modelling research, both internationally and within FOI, is given. A few selected materials modelling methods which are of great interest for sensor applications are described at some length. Finally, a vision for future materials modelling research at the division of Sensor Technology is presented, along with a few generic project proposals.