A Lesson from Reptiles: How a Snake’s Motion Can Inspire Better Robots

There’s no doubt about it, robotics is here to stay. An estimated $103 billion went into robotics research in 2018 to solve some pressing issues associated with the design of autonomous robots. One such problem was the difficulty associated with a robot’s motion on granular surfaces such as sand, rubble or leaf litter. According to a new study, snakes have a lot to teach us about seamless mobility on complicated surfaces.

Diffraction pattern of snakes moving through an obstacle course (source: Georgia Tech)

In the study, which closely monitored the movement of eight Western shovel-nosed snakes through an obstacle course containing six force-sensitive pegs, researchers observed that when the snakes collide with obstacles, they behaved like light waves encountering a diffraction grating.

The research discovered that snakes do not intentionally change direction when they encounter an obstacle. Instead, the change in trajectory is due to a passive mechanism governed by the animal’s muscular and skeletal systems. In order words, the snake doesn’t send a signal to the associated muscle to alter its shape; rather, the muscle responds to the pressure of the obstacle and deforms accordingly to pass through.

The snake operates an open-loop motion model in that it presets a specific motor program for its body, which is revealed as the characteristic wave-like pattern. When it does encounter an obstacle, the body mechanics enables it to deform without degrading its speed.

This discovery of the cardinal role of passive dynamics in the snake’s motion can help developers in the design of snake-like robots capable of navigating complex terrain with more fluidity. The design of such robots will significantly improve the success rates of search and rescue missions.

This study was carried out by Georgia Tech researchers with support from the National Science Foundation, Defense Advanced Research Projects Agency, the Army Research Office, and a National Defense Science and Engineering Graduate Fellowship. The full details of their findings were published in the journal Proceedings of the National Academy of Sciences.

For more robotics news, check out How to Pick, Pitch and Purchase Your First Industrial Robot.