Scientists have wondered why certain snakes can slither effortlessly throughout the desert, while others have difficultly sliding up desert slopes. Researchers used robotics to solve the mystery and to see what makes some snakes move the way they do.
Sidewinders are small rattlesnakes that can be found in southwest U.S. and the northwest of Mexico. Sidewinder snakes move themselves up one body section at a time, similar to how one would crawl in a trench. These snakes move in a way that is effective, but is different compared to other snakes.
A team of researchers from Georgia Tech, Carnegie Mellon, Oregon State and Zoo Atlanta used a robotic model to better understand why sidewinder snakes use their unusual method to climb up.
"Sidewinding just seems so weird and unnecessary," says Dan Goldman, co-author and associate professor of physics at Georgia Tech. "Why use this crazy movement pattern? But as it turns out, they have a good reason."
The researchers used the robot sidewinder snake to stimulate how the real-life reptiles would move through the sand. The robot snakes were placed into a specially designed tank that replicated desert sand dunes.
Developed at Carnegie Mellon, the robot snake mimicked movement of sidewinders on flat sand, but like the real sidewinders, sandy inclines caused the fake snakes some difficulty.
Published in Science, the researchers found that the snakes move by waving down their bodies not only side-to-side, but also up and down, and each movement made was at a 90-degree angle from the previous wave. The snakes can therefore control how much their body comes into contact with the sand, as they adjust themselves at different angles of the incline.
"This type of robot often is described as biologically inspired, but too often the inspiration doesn't extend beyond a casual observation of the biological system," study co-author Howie Choset, Carnegie Mellon professor of robotics. "In this study, we got biology and robotics, mediated by physics, to work together in a way not previously seen."
Even though the researchers discovered what makes sidewinders slither up slopes the way they do, their research also shows that this type of robotics can be used in real-life scenarios, such as in hard to reach locations during search-and-rescue missions.
"Our initial idea was to use the robot as a physical model to learn what the snakes experienced," says study co-author Daniel Goldman from the Georgia Institute of Technology. "By studying the animal and the physical model simultaneously, we learned important general principles that allowed us to not only understand the animal, but also to improve the robot."
Because people "can almost drive them around like a car," the robots could be used for space exploration on planets with unique terrains. The movement methods used in the snake robot could help others develop more improved navigation and locomotion systems.
