In this video clip, Stefan Hecht motivates his group’s research in smart light-responsive materials and explains in simple terms the underlaying principle of photoswitchable molecules. Specifically, he illustrates the main concept of using light to change one form of the photoswitch into another one and vice versa – without the need for sophisticated chemical formulae or physical equations. Finally, he puts this fundamental concept into perspective to his own work carried out in collaboration with other research groups.