A robot snake has been developed by scientists in the race to advance the abilities of search and rescue machines.

It is hoped that the robots may some day help to explore inaccessible terrain, such as rubble after an earthquake.

Scientists observed how snakes moved and used this information to make a robot that can climb large steps in a nimble and stable fashion.

Chen Li, an assistant professor of mechanical engineering at Johns Hopkins University in the US and a senior author of the research, said: “We look to these creepy creatures for movement inspiration because they’re already so adept at stably scaling obstacles in their day-to-day lives. Hopefully our robot can learn how to bob and weave across surfaces just like snakes.”

Previous studies had mainly looked at snake movements on flat surfaces, but rarely in 3D terrain, except for on trees. Li said these did not necessarily account for real-life large obstacles such as pieces of rubble and debris that search and rescue robots would have to scale.

Researchers studied how the variable kingsnake – commonly found in deserts and pine-oak forests – climbed steps in Li’s terradynamics lab. “These snakes have to regularly travel across boulders and fallen trees – they’re the masters of movement and there’s much we can learn from them,” he said.

The study has been published in the Royal Society Open Science journal.

Through a series of experiments it was found that the snakes partitioned their bodies into three sections. The front and rear body of the snake wriggled back and forth on the horizontal steps like a wave, while the middle body section remained stiff, hovering to bridge the large step.

Scientists noticed the wriggling portions provided stability to keep the snake from tipping over. As more of the snake reached the step, its front body section would get longer and its rear section would get shorter while the middle body section remained roughly the same length, suspended vertically above the two steps.

If the steps got taller and more slippery, the snake would move more slowly and wriggle their front and rear body less to maintain stability.

The team created the robot to mimic the snakes’ movements. They say that compared to robot snakes from other studies, their creation is more stable than all but one, and came close to matching a real snake’s speed.

But the body suspension system – needed to keep the robot stable on large steps – means the robot uses more electricity. Li said: “The animal is still far more superior, but these results are promising for the field of robots that can travel across large obstacles.”