Fingerprint is an impression of the friction ridges of all part of the finger. A friction ridge is a raised portion of the epidermis on the palmar (palm) or digits (fingers and toes) or plantar (sole) skin, consisting of one or more connected ridge units of friction ridge skin. Fingerprints may be deposited in natural secretions from the eccrine glands present in friction ridge skin or they may be made by ink or other contaminants transferred from the peaks of friction skin ridges to a relatively smooth surface such as a fingerprint card. The term fingerprint normally refers to impressions transferred from the pad on the last joint of fingers and thumbs, though fingerprint cards also typically record portions of lower joint areas of the fingers. In this study, fingerprints over various metals like aluminium (Al), copper (Cu) and silver (Ag) and non metals like thin plastic film, mica etc. have been investigated and an approach was made to interpret the results in terms of various laws... Это и многое другое вы найдете в книге Thermodynamics in fingerprinting (Vaneet Dhir)