Neutrons are intensively used for materials research at PSI because they enable unique and non-destructive access to the interior of materials on a scale ranging from the size of atoms to objects a centimetre long. They therefore serve as ideal probes for investigating fundamental and applied research topics, such as quantum spin systems and their potential for application in future computer technologies, the functionalities of complex lipid membranes and their use for the transport and targeted release of drug substances, as well as the structure of novel materials for energy storage as key components in intelligent energy networks.