Use of atomic force microscopy for high-resolution non-invasive structural studies of human hair

The morphology of the fine cuticular structure of human hair has traditionally been investigated using scanning electron microscopy and transmission electron microscopy. Although these techniques are very useful, they require specimens to be coated with metallic films or to be suitably stained. In addition, high vacuumc onditions are required that may damage or alter the appearance of delicate cuticular structures. Atomic force microscopy is a relatively new scanning probe technique, capable of imaging surfaces at high resolution under ambient conditions. In this communication, the potential application of atomic force microscopy for structural investigations of human hair surfaces are discussed. Fine surface structuress, such as the exocuticle, the endocuticle, and the marginal band (A- or a-layer), could be easily identified. The technique has also been demonstrated to image hair surfaces in liquid environments, opening the way to in situ studies of the effects of hair-care products and treatments.