Light-controlled material changes shape in 1D, 2D, or 3D on demand

Japanese researchers at Chiba University have developed a novel supramolecular polymer system capable of dynamically changing its structure in one, two, or three dimensions by modulating light intensity. This material combines a light-responsive azobenzene unit with a barbituric acid-based merocyanine core, enabling it to exhibit supramolecular polymorphism controlled by light. Initially forming 1D coiled nanofibers, the system naturally transitions into 2D nanosheets under ambient light. When exposed to strong ultraviolet (UV) light, the material reverses back into 1D nanofibers due to photoisomerization disrupting hydrogen bonds, while weak UV light induces the formation of 3D nanocrystals through Ostwald ripening, where smaller nanosheets dissolve and redeposit onto larger ones. This research addresses a fundamental challenge in materials science: creating out-of-equilibrium molecular assemblies that adapt their structure based on the amount of energy input, mimicking living organisms. The ability