Another use of mica is in the production of ultraflat thin film surfaces (e.g. gold surfaces) using mica as substrate. Although the deposited film surface is still rough due to deposition kinetics, the back side of the film at mica-film interface provides ultraflatness, when the film is removed from the substrate. Such ultraflat substrates are common substrates for sample preparation for the atomic force microscopy. Freshly cleaved mica surfaces have been used as clean imaging substrates in atomic force microscopy, enabling for example the imaging of bismuth films,plasma lycoproteins, membrane bilayers, and DNA molecules.
