Scientists from Trinity College Dublin and AMBER, the Science Foundation Ireland-funded materials science research centre hosted in Trinity College Dublin, have created ‘molecular cages’ that can maximise the efficiency of converting molecules in chemical reactions, and that may in future also be used as sensors and drug-delivery agents. The cages can be packed with different molecules, many of which have a specific task or functionality. Incredibly, a teaspoon of powder containing these cages provides a greater internal surface area to boost reactivity and storage capacity than would be provided by an entire football field (4000 m2/g).