If you want to see, up-close, how your product or hair styling device affects the surface of the hair, or how an ingredient spreads over the hair fiber, you may consider using scanning electron microscopy (SEM).

SEM allows visualization of the hair surface at a very high level of magnification, beyond that possible with light microscopy.  It is ideal for helping describe hair damage effects to consumers e.g. grooming damage, heat styling damage, split-ends, chemical damage etc.  It can also be used to investigate particulate and polymer deposition on the surface of the hair.