Conventional explanations for why humans have fingerprints have suggested help in gripping things and possible benefits for the sense of touch. Now Georges Debrégeas and colleagues at the Ecole Normale Supérieure have used an artificial fingertip and a vibration sensor to lend support to the second of these explanations. Using small pieces of skin-like rubber with either a smooth surface or one patterned like a human fingerprint, they looked at how it vibrated when dragged across a glass slide etched with fine lines.

The results showed that the "fingerprints" produced vibrations up to 100 times stronger. The vibrations were strongest when the etched glass slid perpendicular to the "fingerprint" ridges. This suggests that the geometric lines of real fingerprints developed to boost the chances of rubbing some of the ridges across surfaces in an optimal way.

Further reading

J Scheibert et al. 2009 Science 323 572.