Monkeys, apes and we humans have evolved fingerprints or ridges on hands and feet. This region on our hands and feet also has a high density of sweat glands.
A new study has now shown that these ridges and the skin moisture due to the sweat glands helps give greater levels of grip when holding on to objects. Fingerprint ridges help increase the friction when you hold smooth surfaces and the sweat is also regulated to maximise friction.
The results were published in the Proceedings of the National Academy of Sciences.
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Co-author Mike Adams, Professor in Product Engineering and Manufacturing, at the University of Birmingham commented: "Understanding the influence of finger pad friction will help us to develop more realistic tactile sensors — for example, applications in robotics and prosthetics and haptic feedback systems for touch screens and virtual reality environments."
Using hi-tech laser-based imaging technology, the scientists found that the moisture on the finger is regulated by a combination of sweat pore blocking and accelerated evaporation of excessive moisture from external wetting. These two functions together maintain the optimum amount of moisture in the fingerprint ridges.
"This dual-mechanism for managing moisture has provided primates with an evolutionary advantage in dry and wet conditions — giving them manipulative and locomotor abilities not available to other animals, such as bears and big cats," added Professor Adams.
