Scanning electron microscopy (SEM) is a surface analytical technique used to generate magnified topographic images of a material surface from 20X to over 100,000X. SEM uses a focused beam of high-energy electrons to generate a variety of signals at the surface of solid specimens. The field-emission cathode in the electron gun of a SEM provides narrower probing beams at low as well as high electron energy, resulting in both improved spatial resolution and minimized sample charging and damage. The signals that derive from electron-sample interaction reveal information about the sample including external morphology (texture), crystalline structure and orientation of materials making up the sample.
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SEM is often used to visualize the surface of hair under high magnification and picture the condition of protective cuticle scales. This technique can also provide information about the morphology of deposited surface coatings. TRI has a long history in this area with a selection of our images appearing in Clarence Robbins' "Chemical and Physical Properties of Hair" book - which is often considered the primary text on hair science.

 

The SEM used is a FEI XL30 FEG-SEM equipped with an EVEX EDS. This high-resolution field-emission SEM has an optimum image resolution of 2nm and is accessed completely using a computer terminal.