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This story is from the category Sensors
Date posted: 30/11/2009 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. There have also been hints that fingerprints play a role in the sensation of touch. One possibility is that when a finger is moved across a surface, each ridge in a fingerprint acts like a tiny lever, magnifying the subsurface strain for the nerve endings beneath. Today, Georges Debregeas et amis at the University of Paris 6 and 7 say that's only part of the story. In fact the role that fingerprints play in touch is far more important and subtle than anyone imagined. Debregeas et amis say it looks as if the ridges and whorls in fingerprints filter mechanical vibrations in a way that best allows nerve endings to sense them. The mechanoreceptors that do this job are called Pacinian corpuscles. They sit at the ends of nerves and are responsible for sensing pressure and pain. These devices can sense vibrations over a wide area of skin but are sensitive only to a limited range of vibrations. In fact biologists have known for some time that Pacinian corpuscles are most sensitive to vibrations at 250Hz. See the full Story via external site: www.technologyreview.com Most recent stories in this category (Sensors): 14/06/2013: Autonomous energy-scavenging micro devices will test water quality, monitor bridges, more |
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