WHAT ARE FINGERPRINTS ?

What are fingerprints ?
The furrows at our fingertips, they also help bring us to avoid things slide, we help to feel fine textures and tiny show relief of French researchers in the latest issue of the journal Science.

Previous studies had shown that this ability to feel fine structures less than 200 micrometers or roughly the width of a human hair, involves vibration of the skin that occur when our fingers move on a surface. To see how these vibrations are translated into sensation Schiebert Julien and his colleagues have developed a mechanical sensor with an elastic coating that can be either smooth or wrinkled as our fingertips. When the sensor with "footprint" was slipped on various surfaces, the vibration that developed had a frequency recognized by nerve endings in the skin called "Pacinian corpuscles". These particles are connected to sensory neurons, which then transmit the signal to the brain. If the Pacinian corpuscles are known to intervene in the fine sensations, another type of nerve terminal is involved to feel coarser structures.

A surface with fingerprints, but not smooth, the researchers report, is thus amplify and filter certain frequencies of vibration, allowing the nervous system to detect the signal.