Knit me a car

THE Leipzig factory that makes BMW’s electric cars is uncannily quiet. There are no thundering machines stamping out steel body panels or robots welding them together in showers of sparks. The process owes more to knitting than metalbashing. The cars begin life in a Japanese rayon factory as spools of plastic that look a bit like fishing line. This “precursor”, as it is called, is unwound in America, baked into strands of carbon fibre and then spun into a yarn. In Germany the yarn is woven into sheets. When the sheets arrive in Leipzig they are shaped, pressed and cured with resin to form stiff, light body parts which are glued together by robots.The carmaker is in the vanguard of a materials revolution, which is powered by a growing understanding of the properties of substances at the smallest scale. In roughly five years from now, scientists will have set out what some call the “materials genome”—a database with the properties of all known and predicted compounds. Instead of searching for materials that have the right qualities for a job—a quest that has usually depended mostly on trial and error—researchers will first define what they want, and their computers will then compile a list of materials that seem to fit the bill.