Kostya Novoselov has the tour down pat. After a friendly introduction, visitors are whisked to a clean room so that they can repeat the experiment that helped to win him a share of the Nobel Prize in Physics in 2010. The important bit can be done in seconds: press some sticky tape onto a chunk of graphite, then press it again onto an ultraclean silicon wafer. Peel it off, and some of the silver flakes dotting the wafer’s surface are atom-thick sheets of honeycombed carbon known as graphene.