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Many human inventions are based on things found in nature. Velcro was inspired by the burrs a Swiss engineer found on himself and his dog, airplane wings by birds in flight. A new study of elephant trunks found something that could be useful, too - specialized whiskers. NPR's Nate Rott reports.
NATE ROTT, BYLINE: Elephant trunks are incredibly versatile.
ANDREW SCHULZ: They can pick up tortilla chips without breaking them. They can lift up a giant barbell. People have seen them lift trees.
ROTT: Andrew Schulz is a researcher at the Max Planck Institute for Intelligent Systems in Germany.
SCHULZ: I primarily study animals and materials and try to understand how we can design different types of engineered materials and robotics based on animal structures.
ROTT: For about eight years, Schulz has focused on elephants, specifically their trunks, which, much like a human arm, are covered in tiny hairs, only they're not normal hairs.
SCHULZ: A normal hair, the follicle that it's in - right? - is just basically this hair follicle.
ROTT: Nothing special. Whiskers, though, like you see on your cat, your dog, or that unwanted rat in the attic...
SCHULZ: They are in this follicle that has this blood sinus, and it's connected to all of these mechanoraceptors.
ROTT: Receptors that detect things like touch, pressure or vibration and convert them into electrical signals that a brain can understand, conveying information basically to the animal about their surroundings. Schulz says he often thinks of whiskers as being kind of like the sideview mirrors of a car.
SCHULZ: So even though cats and dogs have eyes - right? - these whiskers are covering the blind spots so these animals are not going to run into anything.
ROTT: For elephants, whiskers essentially extend and enhance their sense of touch, allowing them to delicately pick up that tortilla chip without damaging it. But to understand how those whiskers do that, Schulz and his collaborator decided to look at them at the microscopic level.
SCHULZ: And it actually confused us quite a bit.
ROTT: The base of the whiskers were stiff.
SCHULZ: Like, almost as stiff as plastic.
ROTT: And they're hollow with these little channels inside of them, like the inside of a horse hoof or a ram's horn. But then, as you move down towards the tip...
SCHULZ: It's incredibly soft, so soft as rubber, and then that is completely dense. And one of the things that we think is that this gradient structure of the whiskers helps them know exactly where something is touching along the length.
ROTT: Schulz says the findings, published in the journal Science, expand our understanding of touch and could be useful for engineers trying to make new mechanical tools or robots. For example, he says, think of a future robot at the grocery store trying to pick out a ripe fruit.
SCHULZ: If we take something like a bio-inspired whisker, you can have a soft, delicate tap so that you're able to not damage the fruit.
ROTT: While the stiff base conveys data about its ripeness, which I guess beats squeezing the heck out of an avocado and hoping nobody sees you put it back. Nate Rott, NPR News.
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