Professor Robert Langer is the most cited engineer in history and 2015 winner of the Queen Elizabeth Prize for Engineering. He is best known as the Co-Founder of Moderna, the biotech start-up that was one of the first companies to pioneer the mRNA vaccines (used to tackle Covid-19). His innovations, including controlled release drug delivery systems and tissue engineering, have transformed a variety of medical treatments, enabling victims of serious accidents to re-grow missing tissue, and increasing the accuracy of treatment for brain cancer.