Fingerprint ridge width is coupled to Pacinian resonance

French scientist Georges Debregeas has published a finding that the width of the ridges of our fingerprints just happens to be optimized for maximally vibrating our nerve endings:

The latest evidence suggests that fingerprints process vibrations in the skin to make them easier for nerves to pick up. They may seem little more than digital decoration, but biomechanics have long known that fingerprints have at least one use: they increase friction, thereby improving grip…

In fact the role that fingerprints play in touch is far more important and subtle than anyone imagined.

…Biologists have known for some time that Pacinian corpuscles are most sensitive to vibrations at 250Hz. So how do fingers generate this kind vibration? Biologists have always assumed that humans can control the frequency of vibrations in the skin by changing the speed at which a finger moves across a surface. But there’s little evidence that people actually do this and the Paris team’s discovery should make this view obsolete.

…They say that fingerprints resonate at certain frequencies and so tend to filter mechanical vibrations. It turns out that their resonant frequency is around 250 Hz. What an astonishing coincidence!

That means that fingerprints act like signal processors, conditioning the mechanical vibrations so that the Pacinian corpuscles can best interpret them…

The article also notes that in robotics this is called morphological computation; that is, computation through interactions of physical form.

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