DNA metabolism is governed by a delicate balance between compacting the stored genetic information while simultaneously ensuring a highly dynamically access to it. This interdisciplinary project aims (i) to understand the mechanics and dynamics of chromatin as well as the mechanism of enzymes involved in DNA metabolism on a molecular level and (ii) to develop new nanometric tools based on optical methods and 3D DNA nanostructures that allow addressing new experimental questions. Within the research project novel nanoscopic detection assays based on the combination of magnetic tweezers and optical methods shall be developed, such as ultra-fast torque spectroscopy and combined FRET-force spectroscopy. Our single-molecule assays shall be applied to study the material properties of self-assembled 3D DNA nanostructures, which shall then be used to set up improved high resolution single-molecule assays. These technological improvements will become key to obtain insight into structure and dynamics of in vitro reconstituted chromatin as response to external mechanical stress but also into the operation of molecular motors that themselves generate forces and torques on DNA and chromatin. The main goal of the project is to use nanotechnological tools to understand design principles of biomolecules, biomaterials and biological motors, which in turn shall be used to develop smarter nanotools and functional elements.