Modeling fingerprint formation
Michael Kücken
Theoretische Physik II, Universität Bayreuth, Universitätsstr. 60, 95440 Bayreuth, Germany
The uniqueness of fingerprints (epidermal ridges) has been recognized for over two thousand years. They have been studied scientifically for more than two hundred years. Yet, in spite
of the accumulation of a wealth of empirical and experimental knowledge, no widely accepted explanation for the development of epidermal ridges on fingers, palms and soles has yet emerged.
Informed by an extensive literature study we suggest that fingerprint patterns are created as the result of a buckling instability in the basal cell layer of the fetal epidermis.
Analysis of the well-known von Karman equations informs us that the buckling direction is perpendicular to the direction of greatest stress in the basal layer. We propose
that this stress is induced by resistance of furrows and
creases to the differential growth of the basal layer and regression of the volar pads during the time of ridge formation. These theories have been tested by computer experiments. The results are in close harmony with observations. Specifically, they are consistent with the well-known observation that the pattern type depends on the geometry of the fingertip
surface when fingerprint patterns are formed.
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