What is an Electron Microscope?
A microscope is very similar to a telescope or, for that matter, a pair of eye glasses. All microscopes, telescopes, and glasses have something in common – lenses. A lens is usually made out of glass and it takes light and bends it so that we can see things more clearly. In glasses, the lenses will bend the light so that things that appear “fuzzy” are brought into focus. In telescopes, lenses take things that are far away and make them appear as if they are close to us so we can see them better. In microscopes, lenses take things that are very small and magnify them so they become visible.
Light microscopes are used in a number of areas such as medicine, science, and engineering. However, light microscopes can not give us the high magnifications needed to see the tiniest objects like atoms. For this, we have to use electrons rather than light. Electrons are small particles within the atom. Microscopes that use electrons rather than light are called electron microscopes.
Since we are not using light in electron microscopes, we can not use glass for our lenses. Instead we use magnets. Magnets will make electrons bend just as glass makes light bend. These magnets let us magnify images and bring them into focus. Since you can’t really see electrons with your eyes we have to use some other equipment to produce a television signal that shows an image on a tv screen. Your tv at home uses electrons to produce an image, too. A scanning electron microscope really is a big fancy tv attached to some magnets!
Microscope and Telescope picture source: Edmund Scientific Company Catalog