A beam of electrons goes over the surface of a sample that is coated with metal. While electrons act like particles, they also posses wave-like properties. Transmission electron microscopy utilizes electrons with extremely short wavelengths that glass or air would normally scatter. Thus, a vacuum is used, and a magnetic field serves to direct electrons along a specific path toward a focal point. Very thin sections of samples are necessary so the electrons scatter to correspond to the density of structures within a sample.
Dense parts stain more darkly.
Cotton fibers may differ from each other in terms of diameter thickness, length, degree of twisting, wall composition, texture, etc. This study uses scanning electron microscopy to compare the surface characteristics of these different fiber types both quantitatively and qualitatively. Transmission electron microscopy was also used to compare the internal characteristics of the six fiber types qualitatively. For each type, five stubs were coated with the cotton via double stick labels and one stub with carbon tape. All stubs were then coated with a metallic mixture using a sputter coater.