Atomic force microscopy of human hair cuticles: A microscopic study of environmental effects on hair morphology

Abstract

We have used an atomic force microscope to provide quantitative real-time analysis of human hair morphologic changes under ambient conditions. This form of microscopy combins the lateral resolution of an electron microscope and the flexibility of a light microscope. Three experiments were performed: a study of hair morphology in air versus water, a kinetic study of hair hydration, and a determination of how pH changes affect hair morphology. The overlapping keratinized cells that form the hair cuticle spread out between 50 and 150% when hydrated, compared to a total shaft diameter change of 10%. This hydration reaches a saturation point within the first few minutes after immersion. Also, hair swells much more at higher pH.