Future Mars rovers may sport fur, scientists suggest

NASA's Curiosity Mars rover. © NASA / JPL-Caltech / MSSS
Maybe what a brave little Mars rover needs to last longer is some techno-fur, say researchers who have studied the way animals use hair to stay clean and deal with the side effects of being furry.

"Drones and other autonomous rovers, including our machines on Mars, are susceptible to failure because of the accumulation of airborne particles," said David Hu, associate professor at Georgia Institute of Technology, who co-led the research.

"Understanding how biological systems, like eyelashes, prevent soiling by interacting with the environment can help inspire low-energy solutions for keeping sensitive equipment free from dust and dirt," he added.

The research focused on 27 mammals and insects and what strategies they used to keep themselves clean. They had one common feature – hair, which serves various purposes in different species, from keeping warm to enhancing senses, but also gives a combination of pros and cons in terms of getting soiled.

Hairs can keep dirt off the skin, but also provides extra surface area that can get dirty itself. And this addition is quite significant, about 100 times greater than the skin surface area, the scientists said.

"A honeybee's true surface area is the size of a piece of toast," said Hu. "A cat's is the size of a ping pong table. A sea otter has as much area as a professional hockey rink."

Keeping a hockey ring-sized area clean may be a tiresome task, one expects, and the scientists were interested in how the animals take care of it. Some approaches are relatively energy-consuming.

"Dogs shake water off their backs, just like a washing machine," said Ph.D. student Guillermo Amador, who helped Hu run the calculations. "Bees use bristled appendages to brush pollen off their eyes and bodies. Fruit flies use hairs on their head and thorax to catapult dust off of them at accelerations of up to 500 times Earth's gravity."

Other tactics are more efficient, such as eyelashes that keep eyes clean by regulating airflow and funneling particles away, or cicadas that use sharp points on their wings to puncture airborne bacteria.

"They don't do anything extra to stay clean. It just happens," said Amador, who recently graduated.

The study was published in the Journal of Experimental Biology.