Latest news with #JournaloftheMechanicalBehaviorofBiomedicalMaterials
The Hindu
27-05-2025
- Science
- The Hindu
Fingerprints may also wrinkle uniquely
We use many features of our bodies to identify ourselves in government records. Fingerprints in particular are widely used, from unlocking phones with sensors to validating Aadhaar cards. But fingerprints can also be fickle. For example, if you spend an hour in the pool, a fingerprint sensor may no longer be able to read yours. This is because wrinkles will have formed on your fingertips. Unlike raisins, which swell in water, the skin on our fingers contracts, creating a wrinkling pattern on the tips of our fingers. The discovery of this mechanism over two decades ago challenged the idea that wrinkles form when the skin on the finger swells. Upon further probing, scientists found that the shrinking may have evolved to help humans grip objects better underwater. The wrinkling happens because when you are in water, the nerves in your fingertips send signals to the brain, which asks the blood vessels in the fingertips to contract. When Binghamton University associate professor of biomedical engineering Guy German wrote about this for a children's science magazine, a curious student asked: 'Do the wrinkles always form the same way?' This led him to investigating whether the wrinkled pattern is as unique as the fingerprint. In a study published in May in the Journal of the Mechanical Behavior of Biomedical Materials, German and graduate student (recently graduated) Rachel Laytin reported just that. The team found that the pattern is the same for an individual regardless of how many times it is forced to wrinkle. In their test, team members immersed hands in 40° C water for 30 minutes. Then they mapped the wrinkles and compared them to patterns formed 24 hours later, when the test was performed again. There were only a few small differences. While fingerprints are two-dimensional motifs, wrinkling patterns are three-dimensional because they have trough-like low points and groove-like high points. Fingerprints are personal and unique. Even identical twins do not have the same fingerprint. What explains the near-uniqueness of wrinkling patterns? If wrinkles occur because blood vessels beneath the skin have been constricted, then the network of these blood vessels must be unique in all of us. According to German, 'The size and distribution of blood vessels is well known to vary across individuals. However, not enough studies have been performed to definitively say they are different for all humans.' If the wrinkles can be used to identify people, it could be used in place of fingerprints, too, especially when law enforcement officials have to identify cadavers found in water, and to quickly identify victims following water-based disasters like floods and tsunamis. One gap is that there doesn't seem to be a relationship between wrinkle patterns and fingerprints. Until such a mapping is found, the wrinkle pattern will constitute a separate instrument of identification — something government agencies could record after collecting one's fingerprints as well. Shrivaishnavi Ranganathan is a science-educator-turned-writer.
Yahoo
14-05-2025
- Health
- Yahoo
Mystery About The Way Fingers Wrinkle in Water Might Have an Answer
Upon learning about the blood vessels responsible for our water-soaked finger wrinkles, young readers of The Conversation's Curious Kids series had further questions for scientists: "Do the wrinkles always form in the same way?" one asked. "And I thought: I haven't the foggiest clue!" recalls the author of the educational article, biomedical engineer Guy German from Binghamton University in New York . "So it led to this research to find out." German and his colleague Rachel Laytin recruited three volunteers to soak their fingers for 30 minutes. Images confirm the patterns of looped peaks and valleys adorning the participants' sodden fingertips mostly repeated themselves when they were soaked again 24 hours later. As water seeps through open sweat ducts into our skin, it eventually decreases the concentration of salt in our outer layer. Nerve fibers alert the brain to this change in skin condition, which then triggers our bodies' automatic blood vessel retraction. When these tiny skin vessels shrink, they drag the surface of our largest organ down with them, shriveling once-smooth fingers and toes into a rougher, pruney texture. "Blood vessels don't change their position much – they move around a bit, but in relation to other blood vessels, they're pretty static," explains German. "That means the wrinkles should form in the same manner, and we proved that they do." This puckering isn't just a random side-effect either. The morphological changes create a measurable advantage in wet conditions: the skin's temporary grooves and ridges provide a better grip, making it easier for us to walk on or grasp sodden things. As these wrinkles give us super grip it seems odd we don't keep them full time. While researchers don't know why this is, they suspect the temporary texture might reduce our finger's sensitivity or make them more vulnerable to injury. It was originally assumed that swelling caused soaked skin to wrinkle, but a study in 2016 revealed our skin would need to swell at least 20 percent for that to happen. What's more, previous research found people with nerve damage don't experience finger pruning, leading to further investigation of the mechanisms involved. "We've heard that wrinkles don't form in people who have median nerve damage in their fingers," says German. "One of my students told us, 'I've got median nerve damage in my fingers.' So we tested him – no wrinkles!" In addition to sating childlike curiosity, such details can assist in forensics. For example, understanding this finger skin distortion could help identify bodies after prolonged water exposure after natural disasters. So we can now add wrinkle topology to the set of consistent patterns that compose our skin, along with fingerprints and hidden stripes we all possess. This research was published in the Journal of the Mechanical Behavior of Biomedical Materials. Record Study Connects Hundreds of Genetic Markers With OCD A Distinct New Form of Diabetes Has Been Officially Recognized Life Expectancy Has Barely Changed in Some US States For More Than a Century
