A group of Swiss and French researchers believe their salamander-like robot provides clues into how early amphibians made the leap from swimming to walking hundreds of millions of years ago.

The development of the robot's spinal cord model may also lead to a greater understanding of how our own nervous system sends signals from the brain to our bodies, the researchers said in a paper published on Friday.

Researchers believe the robot's motion is similar to that of the first animal to crawl onto land from the ocean.
(Biologically Inspired Robotics Group/ EPFL/ A. Herzog/ Associated Press)

Scientists from the Ecole Polytechnique Fédérale de Lausanne (EPFL) in Switzerland and the Institut national de la santé et de la recherche médicale centre at the University of Bordeaux in France introduced their robot, Salamandra Robotica, in the March 9 issue of the journal Science.

The scientists designed the robot based on what they know of a salamander's movements. The metre-long robot has 10 motors driving a body made up of four rotating legs and six joints, all controlled wirelessly from a laptop computer.

The researchers had the robot swim in Lake Geneva and then crawl along the shore.

The robot salamander is a unique example researchers in the separate fields of robotics and biology can work together, the scientists said. Roboticists, for example, can learn how to create different movements from studying different organisms.

"Nature found a nice way of making a sophisticated circuit in the spinal cord and then controlling the muscles from there," said EPFL professor Auke Ijspeert in a statement. "It's a fantastic solution for co-ordinating multiple degrees of freedom in a simple distributed way."

Likewise, robotics allows biologists to test theories about how complex systems like the spinal cord might work and provide insight into how the first amphibians moved from the sea to the land.

In the case of the Salamandra Robotica, for example, the researchers had to make a number of assumptions on how limb and spine movements were co-ordinated, and the creation of the robot allowed them to test these assumptions with a working, moving model.

"We used the robot to show that our model actually reflects reality," said Ijspeert. "The robot was very useful to validate that our model could effectively modulate speed, direction and gait — aspects that need a mechanical 'body' to be properly evaluated — and also to verify that the generated movements are close to those of a real salamander."

Ijspeert said the research may point scientists toward a better understanding of the more sophisticated circuits in the human spinal cord.

With files from the Associated Press