The science of Dermoscopy (also known as dermatoscopy) is used in the medical world to assess medical concerns, including moles, skin tumors, rashes, and other types of skin lesions. Dermoscopes are used extensively for skin cancer detection and prevention with accurate results.
Spectroscopy is the study of the interaction between matter and emitted energy. We're able to determine the skin profile by analyzing how skin structures and features like moisture, oil, glands, melanin, etc. interact with different wavelengths of visible light.
Nanotechnology is the manipulation of matter at an atomic and molecular scale. Using a special effect that occurs with such a manipulation of visible light when it interacts with skin, we create a distinct "fingerprint" of skin structures and are able to decode this signature.