How Does a Scanning Electron Microscopes Work Its Magic?
Image courtesy Ghim Wei Ho and Prof. Mark Welland, Nanostructure Center, University of Cambridge/NSF This image of a “flower bouquet” from a scanning electron microscope is actually a 3-D nanostructure. Scientists are making new materials based on nanotechnology, like these “flowers” of silicon carbide and gallium. In some ways, SEMs work in the same way key copying machines work. When you get a key copied at your local hardware store, a machine traces over the indentations of the original key while cutting an exact replica into a blank key. The copy isn’t made all at once, but rather traced out from one end to the other. You might think of the specimen under examination as the original key. The SEM’s job is to use an electron beam to trace over the object, creating an exact replica of the original object on a monitor. So rather than just tracing out a flat one-dimensional outline of the key, the SEM gives the viewer more of a living, breathing 3-D image, complete with grooves and engr
