Abstract: A combination of chemicals and electromagnetic radiation is used to alter the physical characteristics of keratinic fibers such as mammalian or human hair. A non-irritating, non-reactive disulfide in the form of a solution or gel is first contacted with the hair. Electromagnetic radiation is then applied to the hair to photochemically convert the disulfide into a dithiol. The dithiol breaks the disulfide bonds in the hair so that the hair can be permanently re-shaped.

Abstract: A method for changing a characteristic of a material is provided. The characteristic of the material is determined by the nature of the bond coupling certain molecular components in the material. The material is exposed to electromagnetic energy having a frequency range related to the bond coupling two molecular components in the material. During the time the material is exposed to the electromagnetic energy, stress is applied to the material. As a result, the bond is broken and then subsequently a different bond is formed by the simultaneous application of the stress and the electromagnetic energy. The structure of the new bond is determined in part by the stress.