What did Marie Curie build for the First World War?

Mobile X-ray units - about twenty vehicles fitted with an X-ray machine and a dynamo run off the car engine, which she designed, funded partly by selling her own gold Nobel medals' worth of appeals, and drove to the front herself. They were nicknamed petites Curies.

She also set up around 200 fixed radiological posts and trained roughly 150 women as operators, since there were nowhere near enough radiologists. Something over a million wounded men were X-rayed through the system, which meant surgeons could locate shrapnel and bullets before cutting rather than searching. She learned to drive and to repair the vehicles because there was nobody else to do it.

Her seventeen-year-old daughter Irène worked alongside her, and later won a Nobel Prize of her own. Neither of them used shielding worth the name - it was not understood - and Marie died in 1934 of aplastic anaemia almost certainly caused by the exposure. Her notebooks and even her cookbook remain radioactive enough to be kept in lead-lined boxes at the Bibliothèque nationale, where readers sign a waiver.