Robots to explore the dark flooded depths of old mines

Indium, rhodium, platinum, tellurium and gold: these are some of the rarest elements in the world. From smartphones (which contain a whopping 60 to 64 elements) to hybrid cars, wind turbines and medical equipment, much of the technology we depend upon contains a rich list of elemental ingredients. Meanwhile, demand for traditional metals such as copper and aluminium is rocketing, driven by the rapid growth of emerging economies in Asia and South America. If our voracious appetite for these minerals continues at the current rate then rare earth metals may be mined out in 15 to 20 years, and indium may only have another decade of supplies remaining. Even aluminium could run dry within the next century.