Klaus Müllen joined the Max Planck Society in 1989 as one of the directors of the Max Planck Institute for Polymer Research. His broad research interests range from the development of new polymer-forming reactions to the chemistry of graphenes, dendrimers and biosynthetic hybrids. His work encompasses the formation of multi-dimensional polymers with complex shape-persistent architectures, nanocomposites, and molecular materials with liquid crystalline properties for electronic and optoelectronic devices. He owns about 60 patents and has published more than 1700 papers.