Scientists have found that surfaces inspired by snakeskin are smashing friction-reduction records by a massive 40 percent. The new surfaces are potentially usable as mechanical components in high-performance cars and even for space exploration, according to study findings published in the journal Bioinspiration & Biomimetics.
The skin of lizards and snakes has long been studied by biologists because it provides significant friction reduction with movement. The skin is also very resistant to wear, even in dry and sandy environments.
"If we'd managed just a 1 percent reduction in friction, our engineering colleagues would have been delighted; 40 percent really is a leap forward and everyone is very excited!" said lead researcher Dr. Christian Greiner in a statement.
Researchers didn't use actual snakeskin for the tests, though. Instead, they used a laser to etch the surface of a steel pin so the texture resembled that of snakeskin. Afterward, they tested the friction that was created when the pin moved along another surface, finding that it offered a massive 40 percent reduction in friction.
The applications that this technique could be applied to are almost limitless. The team, however, plans to implement it in mechanical parts built to a micro or nano scale.
Surfaces modeled after snakeskin could also be very helpful in the high-end auto world, such as in Formula 1 cars, in which ever tiny part makes a huge difference. Another industry to take an interest is robotics — especially in the design of robots inspired by snakes themselves.
This presents a new problem in creating a surface that's only friction-resistant in one direction. Actual snakeskin has scales, which all lie in the same direction, resisting backward motion. The surface on the steel pins, however, resists friction in at least two directions.
To solve this problem, Dr. Greiner is looking into using polymers that mimic snakeskin even further, only resisting friction in one direction.
Of course, the surface isn't perfect. While oils or lubricants might previously have been used to reduce friction, this new surface actually doesn't work as well in environments where oils and lubricants are present. In fact, the surface created three times more friction with a lubricant than it would have without.
"This wasn't a huge surprise, since we were looking to nature for inspiration and the species we mimicked – the royal python and a lizard called a sandfish skink – live in very dry environments and don't secrete oils or other liquids onto their skin," Dr. Greiner explained.
