Physicists in Japan, Spain and the Czech Republic have developed a new type of atomic force microscope (AFM) that can "fingerprint" the chemical identity of individual atoms on a material's surface. This is one step ahead of existing AFMs, which can only detect the position of atoms. The device determines local composition and structure using a precise calibration method, and can even be used to manipulate specific atomic species -- a feature that could enable nanostructures to be constructed "atom by atom" (Nature 446 64).