Research says: human skin is like rubber, fingerprint ridges do not enhance hand grip!

Research says: human skin is like rubber, fingerprint ridges do not enhance hand grip!

Skin is like rubber, fingerprints do not enhance hand grip: The role of the skin on our fingertips, palm and soles of the feet is to grip other objects, and they all have characteristic “friction” ridges. Nevertheless, very little research has been carried out about how well fingers perform, how friction is achieved and why we have soft fingerpads with fingerprints at all. Recent research carried out in the laboratory of the University of Manchester suggests that finger skin has frictional properties rather like rubber.

Why do we have fingerprints? The most likely possible answers are: 1) Fingerprints may increase friction on rough materials; 2) Fingerprints may increase friction on wet surfaces by channeling away water like a car tyre; 3) Fingerprints may help prevent blistering by allowing shear of the skin. New British research indicates that the first option can be deleted from the list. Researcher Dr. Roland Ennos explains his findings below: “I have been thinking about this for years and, having played around with it for a bit, realised that skin is rubbery so the ridges in fingerprints might actually reduce grip. Our experiments – using a plastic cup, weights and strips of Perspex (acrylic glass) to develop a simple machine in the lab – proved me right. The experiment was so simple, this discovery could have been made 100 years ago; but scientists make assumptions and tend to look at complicated things instead. We are now testing that theory and two others, that fingerprints improve grip on rough surfaces and that they increase sensitivity. There are potential spin-offs for this work. For example some people who suffer nerve damage that prevents sweating have slippery fingers and cannot grip: we could develop something to treat that.” LEARN MORE ABOUT FINGERPRINTS: • Fingerprints reveal identity, drugs & lifestyle! • Do identical twins have identical fingerprints? • Fingerprints unlikely increase hand grip friction! • Research: fingerprints are unlikely to increase ‘grip’ to our hands! • More finger news!

Research: fingerprints are unlikely to increase ‘grip’ to our hands!

In may 2009 Dr Roland Ennos and his team at The University of Manchester presented fingerprints findings with a surprizing outcome. Fingerprints do not help primates grip, as previously thought. Instead, a fingerprint actually reduces the friction needed to hold onto flat surfaces. Dr Ennos disproved the long-held assumption that fingerprints help primates to grip with a simple machine, three strips of perspex and the right hand of Masters student Peter Warman. They tested the student’s grip on every finger + thumb at three different widths of perspex as the machine pulled the perspex strips down via a weight in a plastic cup. The researchers also tested grip at three different angles by bending both the fingers + the thumb. This wide range of testing conditions allowed them to separate pressing force from the contact area and overcome any confounding variables. The results indicate that fingertips act more like rubbers than hard solids; their friction coeficient fell at higher normal forces and friction was higher when fingers were held flatter against wider sheets and hence when contact area was greater. WHY DO WE HAVE FINGERPRINTS? Dr Ennos answers the question as follows: “The experiment was so simple, this discovery could have been made 100 years ago; but scientists make assumptions and tend to look at complicated things instead. My preferred theory is that they allow the skin to deform and thus stop blistering. That is why we get blisters on the smooth parts of our hands and feet and not the ridged areas: our fingerpads, palms and soles.” SUGGESTIONS FOR LEARNING MORE ABOUT FINGERPRINTS: • The latest news about fingerprints! • Evolutionary hand analysis: the mystery of the 5 fingers! • 20 Facts about your fingerprints, skin & dermatoglyphics!