Minneapolis shop owner Bonnie Kane spends her days getting drenched while giving dogs baths at Royal Pet Beauty. Hosing dogs down for 30 years, she knows that when a dog gets wet, the first thing they want to do is shake off. But she never realized how drying-efficient it was for them to do so.
“Once they feel the water start hitting them, they generally start shaking, and the colder the water the more they shake,” says Kane. “Some of them shake so uniquely. It’s pretty funny.”
Scientific research has shown that the loose-hanging skin on furry mammals allows them to dry up to 70 percent in just milliseconds! Most dog owners might find that hard to believe when they’re so familiar with the trail of water Rex leaves after shaking and escaping the bathroom.
Georgia Tech scientists believe their studies might allow engineers to design more efficient washing machines, dryers, and other spinning machines based on nature’s quick-dry system. It might even be applicable to space technology and other robotics. Researcher David Hu noted that the Mars Rover’s power was decreased when dust built up along its solar panels. Implementing shaking may help combat that.
Hu’s team used high-speed cameras to observe the slow motion physics behind shaking in 16 mammalian species. They found that smaller mammals like mice retain more water (proportionate to their size) and must shake faster. A grizzly bear moves its skin four times per second, while a mouse can shake its fur an astonishing 27 times a second!
The scientists found that although a dog’s spine can only rotate 30 degrees in either direction, all that squishy, flabby skin can go a full 90 degrees. If a dog was unable to shake, it would have to spend at least 20 percent of its food energy each day to evaporate water, which would take much longer. This would be akin to a human having to walk around in wet clothes on a cold day.
While we might not enjoy getting a secondhand bath from our dogs when they leap out of the tub, it’s worth remembering that because of our new-found knowledge, we may soon have dryers that get the job done in half the time.
