An international team led by Empa and ETH Zurich researchers is playing with shape-engineered nanoscale building blocks that are up to 100-times larger than atoms and ions. And although these nano “Lego bricks” interact with each other with forces vastly different and much weaker than those holding atoms and ions together, they form crystals all by themselves, the structures of which resemble the ones of natural minerals. These new mega-crystals or superlattices that are depicted on the cover of the latest issue of “Nature” exhibit unique properties such as superfluorescence – and may well usher in a new era in materials science