In 1974, the University of Melbourne's chemistry professor Richard Robson had the idea of replacing the wooden balls and metal rods used in structural models with molecules and chemical bonds. He began experimenting with copper ions linked by a four-armed organic molecule, creating a structure with a cavity. His work laid the foundation for metal–organic frameworks (MOFs), a class of porous materials formed by linking metal ions with organic molecules. Their pores can capture pollutants, support chemical reactions and store gases, giving MOFs a wide range of potential applications.