Scientists in Germany develop a method for extracting from plants an element used in everything from smart phones to parking sensors for vehicles. Edward Baran reports.
Scientists in Germany have come up with a method for extracting the precious element germanium from plants. The element is a semi-conductor and was used to develop the first transistor because it is able to transport electrical charges extremely quickly. Nowadays, silicon-germanium alloy is indispensable to modern life, crucial in making computers, smartphones and fibre-optic cables. Transparent in infra-red light, germanium is also used in intelligent steering systems and parking sensors for vehicles. Yet although germanium is present in soil all over the world, it is difficult to extract, and most supplies currently come from China. Now scientists at Freiburg University of Mining and Technology think they have found a revolutionary way to obtain it from their own soil - with a little help from the natural world. "In German we call it 'mining with plants'. We want to bring elements that are present in the soil into the roots and shoots of the plants, harvest them and then extract these elements from the plants after they have been used for energy, that is to say fermented." The potential for industry could be enormous, but there is still work to do before the benefits can be reaped. At the moment germanium can only be harvested in extremely small quantities, just a few milligrams per litre. Scientists need to achieve at least one gram per litre, which at the moment is only possible through a process of concentrating the extract.