Why Do We Have Fingerprints?

Apr 04, 2009 by Lisa Zyga weblog
Fingerprints
The grooves in fingerprints enhance our ability to sense textures, according to a recent study. Image credit: Wikimedia.

(PhysOrg.com) -- Unlike most wrinkles on our bodies, which appear due to bending and stretching of the skin, fingerprints aren't the result of repeated motion. Each of us is born with a unique set of them, although scientists aren't exactly sure what purpose fingerprints serve.

One possible purpose of is that they improve our . In a recent study, scientists have investigated this idea by performing a series of experiments with artificial fingertips made of rubber-like sensors. The scientists compared the sensitivity between these grooved artificial fingertips and a smooth skin-like material, and found that the grooved fingertips produced vibrations up to 100 times stronger than the smooth material when sliding against a slightly rough surface.

The researchers, from the Ecole Normale Superieure in Paris, explained that increased vibrations give us an enhanced sense of touch, especially for detecting textures. As you rub your fingers across a textured surface, your fingerprints specifically amplify vibrations in an optimized frequency range to stimulate the Pacinian corpuscles, which are nerve endings in the skin that detect textures. In turn, texture information allows us to identify objects by touch.

As the finding demonstrates, not only does our (the "software") play a role in tactile computation, but the physical characteristics of the body (the "hardware") also enhance the computation when sensing.

However, the research doesn't explain why everyone's fingerprints are unique, or why our fingerprints are typically arranged in elliptical swirls. The scientists suggest that the loop design may ensure that some ridges are always brushing perpendicular to a surface, no matter the orientation of the fingertips. In addition, the researchers predict that this work could lead to enhanced tactile feedback for prosthetic hands.

More information: "The Role of Fingerprints in the Coding of Tactile Information Probed with a Biomimetic Sensor." J. Scheibert, S. Leurent, A. Prevost, and G. Debregeas (13 March 2009) Science 323 (5920), 1503. DOI: 10.1126/science.1166467

via: CERN Courier and Science

© 2009 PhysOrg.com

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User comments : 12

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Nartoon
1 / 5 (1) Apr 04, 2009
Could it be they help with grip.
render
not rated yet Apr 04, 2009
Must have something to do with biochemical Chrality.
See:
http://en.wikiped...emistry)
axemaster
2 / 5 (9) Apr 05, 2009
Uhhh... It was shown MANY years ago that they are essentially grippers. Some people are born without fingerprints (yeah weird that), and they have a very hard time gripping smooth objects.

As usual, whoever wrote the article had no idea what they were talking about. Typical physorg.

-Axemaster
Ethelred
3.9 / 5 (7) Apr 05, 2009
There is no reason the it can't be both grip and touch. Grip is obvious but just running my fingers over the table now I can tell my fingerprints are involved in sensing the textures.

Ethelred
fleem
2 / 5 (8) Apr 05, 2009
...especially when your fingers are wet (like grabbing branches covered with the morning dew). The water has a channel through which to squeeze away from pressure points. Otherwise the water would remain as a thin layer preventing any surface-to-surface contact (i.e. it would lubricate).

Agree...typical physorg ignoramity

-fleem
Ethelred
3 / 5 (2) Apr 05, 2009
The signers three:

Ethelred
Fleem
Axemaster

I just notice that both of you also sign your posts. In looking back a bit Axemaster seems to have taken it up lately.

I started doing it a while ago when posting to sites that wouldn't let me use Ethelred for a handle.

Ethelred
Alizee
Apr 05, 2009
This comment has been removed by a moderator.
Paradox
1 / 5 (3) Apr 05, 2009
Just another "Duh!" story.
E_L_Earnhardt
1 / 5 (2) Apr 05, 2009
We are "UNIQUE"! Not only does our "touche" expresss our individuality but there is also a unique signiture in our chemical constuents, our "thought" patterns, etc, etc. "You are most WONDERFULLY made!" Still pushing "accidental creation?"
TheTim
not rated yet Apr 05, 2009
Earnhardt: I don't quite know where you're going with the "unique" argument. EVERYTHING is unique, with no two things in this universe being completely identical to anything else (even identical twins are not absolutely 100% genetically identical).

If we are in fact made in "God's image", god has more faces than my ex during her time of the month...
DonR
5 / 5 (3) Apr 05, 2009
"You are most WONDERFULLY made!" Still pushing "accidental creation?"


God - "Wow, these guys I'm making in my image are bound to commit crimes... I better put an easily visible, distinguishing mark on each of them. When they invent ink, it'll make life heaps easier for their law enforcers... I really wish I could remember why I fitted an appendix though."



Sounds completely feasible to me. And in consideration to my audience, I'll end with...



[/sarcasm]
HappyPhil
4 / 5 (1) Apr 06, 2009
The natural world is constructed with fractal geometry. No two leaves, or snowflakes are exactly alike. The stuff we design and manufacture uses Euclidean geometry, (Circles, Squares, Triangles). The study did, however, create a sensing device based on the general dimensions and spacing of fingerprints that showed a greater signal at the same frequencies that our brain uses for the sense of touch. It seems our fingerprints are enhanced sensory devices.
Ethelred
3.7 / 5 (3) Apr 06, 2009
We are "UNIQUE"! Not only does our "touche" expresss our individuality but there is also a unique signiture in our chemical constuents, our "thought" patterns, etc, etc. "You are most WONDERFULLY made!" Still pushing "accidental creation?"


Evolution is not an accident. You and I are each low probability but that is not the same as accidental. Humans evolved. The evidence is beyond strong.

If we were "WONDERFULLY made!" we wouldn't get cancer. I wouldn't be wearing glasses. Our eyes wouldn't have blood vessels in front of the retina. Our backs wouldn't fail from having evolved originally as a four legged animal.

Evolution works by mutation followed by selection. Both are unavoidable. You and I however are avoidable. Our specific existence is a matter of luck. Not good, not bad, just luck.

Humans are not inevitable. It could just as easily be a bunch of dinosaurs arguing that mammals are inferior to them and that it was the will of their god that they became ascendant.

Ethelred