Nano technologists build such small structures that they cannot be seen with the naked eye. In order to see whether the researcher has actually made what he had conceived, an electron microscope is required. The electron microscope in the photo is a scanning electron microscope. This microscope not only makes the shape of the nanoparticles visible, it also says something about the chemistry. The microscope scans a fine beam of electrons over the sample surface to be examined. The sample produces a variety of electrons and x-rays. The radiation emitted is analyzed. This creates a detailed picture of the shape of the sample, including height differences and chemical composition.