DNA-nanotechnology has created different topologies, including replicable ones, nanomachines, patterns, logic gates, or algorithmic assemblies. Interlocked double-stranded (ds) DNA-architectures like catenanes or rotaxanes, wherein individual components can be set in motion in a controlled manner have not been accessible. These molecules represent long-sought devices for nanorobotics and nanomechanics because they possess a unique mechanical bonding motif, not available to conventional building blocks. The project will apply an unprecedented, simple, and modular interlocking paradigm for double-stranded (ds) circular DNA geometries that we have developed in preliminary studies. This will now be taken several crucial steps forward by generating unconventional DNA-, protein-, aptamer-, and ribozyme hybrid architectures containing interlocked structures wherein the motion of individual components can be controlled in many different ways. We will design, construct, and evaluate switchable autonomous DNA-nanomachines that function as rotational motors, muscles, or switches for powering and manipulating nanoscale components. The DNA machines envisaged in this project will be applied, for example, in synthetic supramolecular self-assembly systems that emulate complex biological machines like motor proteins, nucleic acid polymerases, or ATPases. In addition, they will be developed for multiple purposes in biosensing, logic-gate- and memory circuit assembly, and catalysis. This efficient method for constructing interlocked dsDNA nanostructures opens the exciting possibility of conjoining the area of lifesciences with that of nanomechanical engineering, paving entirely new avenues for nanotechnology. The project is highly interdisciplinary and will open a new field with enormous innovative potential and implications ranging from chemistry to synthetic biology, and from the life sciences to nano-engineering.