While the replica is close to the actual creature, it isn’t a precise reproduction. The amphibian has 40 vertebrae and multiple joints that allow it to rotate freely; but the replica has limited movement, and only 27 motors and 11 segments along its spine. It’s the latest in a line of salamander robots created by the lab, but this model, according to the team, has the potential to give researchers a closer look at how exactly the animals move.
By studying those movements — and 3D printing components that closely mimic a real salamander’s skeletal structure — they were able to reproduce its trademark jerky locomotion with amazing accuracy. Salamanders are amphibians, of course, so claiming that this robot moves like the real thing without making it swim just wouldn’t do. The EPFL team covered all the bases, though, slipping a sort of wetsuit over their ‘bot before turning it loose in a pool of water.
The real genius is in the focus on the spinal cord, which the company says was a decision Ijspeert made himself. The spinal cord controls the motion of the body — not the brain. So, the company set out to mimic the salamander’s movement, hypothesizing that the 3D replica could elucidate how the spinal cord works, and how, specifically, it affects the body. Using electrical stimulation, researchers set a course for the salamander to perform an array of tasks, with the ability to walk functioning at the lowest setting.